practice

Explanation

Administration of doxycycline hydrochloride (antibiotic) can cross react with the normal microflora in the intestine thereby causing dysbacteriosis (an imbalance in the normal microflora). All broad spectrum antibiotics can be associated with dysbacteriosis.

Explanation

Nitrazepam is a hypnotic (tranquilizer) drug from the benzodiazepine family. Other drugs in this family include diazepam, lorazepam, triazolam, oxazepam etc. they facilitate GABA_A action by increasing frequency of Cl^- channel opening. They decrease rapid eye movement (REM) sleep.

Explanation

Amlodipine is a calcium channel blocker (long acting); from the dihydropyridine family.

Atenolol is a β-blocker (cardioselective); Reserpine and Octadine are sympatholytics; Pyrroxanum is an adrenergic antagonist/α-adrenoblocker (non-selective α₁ and α₂).

Explanation

Methotrexate is structurally related to folic acid and acts as an antagonist of that vitamin by inhibiting dihydrofolate reductase (in humans), which is the enzyme that converts folic acid to its active coenzyme form, tetrahydrofolic acid. Trimethoprim and pyrimethamine inhibit the same enzyme but in bacteria and protozoa respectively. This decreases dTMP, needed for DNA synthesis.

Explanation

Vikasol (Menadioni natrii bisulfis) is a synthetic water soluble analogue of Vitamin K. it’s a coagulant. It participates in the formation of prothrombin. It promotes normalization of blood clotting. Indications include acute hepatitis, parenchymal and capillary bleeding, obstructive jaundice.

Dipiridamol – antiplatelet; platelet aggregating inhibitor (it’ll further exacerbate the nosebleed); Folic acid (Vit B₉) is used to treat megaloblastic, macrocytic anemia; Fraxiparin – anticoagulant; Asparcam (panagin): source of K⁺ and Mg²⁺, prescribed for hypokalemia and hypomagnesemia. K⁺ and Mg²⁺ are not important for blood coagulation.

Explanation

Acetylcholine is a neurotransmitter. It increases salivary secretion and stimulates intestinal secretions and motility. It increases bronchial secretions, increases tone of detrusor urinae muscle, causing expulsion of urine, stimulates ciliary muscle contraction (accommodation). It increases exocrine gland secretions (e.g. lacrimal, salivary, gastric acid); gut peristalsis, bladder contraction, bronchoconstriction, papillary sphincter muscle contraction (miosis). Poisoning by cholinomimetics causes diarrhea, urination, miosis, bronchospasm, bradycardia, excitation of skeletal muscle and central nervous system, lacrimation, sweating and salivation. Cholinomimetics are cholinergic agonists which produce analogous effects of acetylcholine.

Explanation

Only myotropic antispasmodics (muscle relaxants) can effectively manage both intestinal colic and essential hypertension. Because sympathomimetics and adrenomimetics will exacerbate hypertension the more. Anticholinesterase agents and M-cholinomimetics will ↑acetylcholine effects in neuromuscular junction → ↑arteriolar smooth muscle tone → exacerbate hypertension. But the myotropic antispasmodics can ↓ muscle tone in intestinal smooth muscle (thereby relieving intestinal colic) and also ↓ arteriolar smooth muscle tone (thereby relieving essential hypertension).

Explanation

Rhodopsin or visual purple is the photosensitive pigment of rod cells. It is made up of a protein called opsin and a chromophore. Opsin present in rhodopsin is known as scotopsin. Chromophore is a chemical substance that develops colour in the cell. Chromophore present in the rod cells is called retinal. Retinal is the aldehyde of vitamin A or retinol. Vitamin A is the name given to a group of related compounds that include retinol (vitamin A alcohol); retinal (vitamin A aldehyde) and retinoic acid (vitamin A acid). Rod cells are responsible for dim light vision or night vision or scotopic vision.

Explanation

Explanation

Doxycycline is a tetracycline, broad spectrum antibiotic. Bacteriostatic; bind to 30s subunit of ribosome.

All other options are not antibiotics.

Toxicity/adverse effect of tetracycline: GI distress, discoloration of teeth and inhibition of bone growth in children, fatal hepatotoxicity; photosensitivity (may cause severe sunburn when patients is exposed to sun or UV rays). Therefore avoid long stay in sun. It is contraindicated in pregnancy. All broad spectrum antibiotics can be associated with dysbacteriosis.

Explanation

Vit. B₃ (Niacin, PP): coenzyme forms NAD⁺, NADP⁺ is derived from tryptophan. Synthesis requires Vit. B₂ and B₆.

Explanation

β₁-adrenoblocker (cardioselective) – Metoprolol: blocks β₁-adrenoreceptors of the heart. Fenoterol β₂-adrenomimetics (short-acting 4-6hrs). Benzylpenicillin – short acting penicillin (β-lactam antibiotic). Nootropil – Nootropic. Morphine hydrochloride – Narcotic analgesic.

Explanation

Potassium permanganate: KMnO₄ →MnO₂ + O₂. MnO₂ has astringent action. O₂  oxidizes proteins in microbes, deodorizing action, antidote action. 0.1% - 100ml for gastric lavage. Chloramines and chlorhexidine bigluconate – nonorganic antiseptic and disinfectant  → chlorine containing (halogens) for treatment of wounds and processing of surgeon’s hands. Sulfocamphocainum – respiratory stimulant.

Explanation

Dimercaprol (unithiol, British anti-lewisite) is used to chelate mercury, bismuth, arsenic and in combination with edentate calcium disodium to treat lead intoxication. It contains two sulfuhydryl (SH-) groups and forms two bonds with metal ions. Administered intramuscularly.

Mannitol – osmotic diuretic; Nalorphine hydrochloride – antidote, blocks opoid receptors and replace opoids from binding with them. Metamizole: analgesic, non-opoid drug. Calcium chloride – Calcium preparation, coagulant with systemic action.

Explanation

Sulfonylurea are insulin secretagogues because they promote insulin release from the β-cells of the pancreas. The primary drugs used today are the 2^nd generation drugs – glibenclamide, glipizide, glimepiride etc. These agents are useful in the treatment of patients who have type 2 diabetes mellitus and cannot be managed by diet alone. Metformin is the only currently available biguanide; its classed as an insulin sensitizer. Acarbose – α glucosidase inhibitor. Butamide (tolbutamide) is also a sulfonylurea but is older and glibenclamide is more potent and used much more commonly. Actrapid (soluble insulin) is fast acting but not a sulfonylurea.

Explanation

Glaucoma: increased intraocular eye pressure. Atropine sulfate (M-cholinoblocker) blocks the acetylcholine response of the ciliary muscle of the eye and of the circular smooth muscles of the iris, producing cycloplegia and mydriasis; it may increase intraocular pressure especially in patients with narrow-angle glaucoma. At low doses, it decreases cardiac rate (bradycardia). Arterial blood pressure is unaffected by atropine but at toxic levels, it will dilate the cutaneous vasculature. It is not effective in promoting healing of peptic ulcer. It can also relieve bronchial asthma. It is contraindicated because its going to further increase intraocular pressure.

Explanation

Diclofenac-natrium(sodium) is a non-selective inhibitor of COX-1 and COX-2. Cyclooxygenase (COX) converts arachidonic acid into the endoperoxide precursors of prostaglandin. COX-1 is present in non-inflammatory cells (normal body tissues); COX-2 is present in lymphocytes, polymorphonuclear cells and other inflammatory cells. Side effects: Gastro-Intestinal (GI) symptoms – bleeding, ulceration and perforation. Because COX-1 is used to produce mediators that help to protect gastric mucosa, whenever COX inhibitors are used they produce these side effects.

Explanation

Explanation

There is structural damage (i.e. affecting organ formation) in a 1^st trimester exposure and functional damage (i.e. affecting organ maturation and/or function) in 2^nd and 3^rd trimester exposures to paracetamol. It is teratogenic because it is able to disturb the growth and development of an embryo or fetus.

Explanation

Acetylcysteine is an expectorant (mucolytic), which ↑bronchial secretion or reduce its viscosity, facilitating its removal by coughing; they loosen cough which becomes less tiring and more productive. This drugs treats the pathogenesis/development of the disease and not its cause (etiology-etiotropic) or symptoms (symptomatic).

Explanation

K⁺ sparing diuretics:

  - aldosterone antagonist: spironolactone, eplerenone

  - inhibit Na⁺ reabsorption: triamterene

     Carbonic anhydrase inhibitor: acetazolamide; Thiazide diuretics: hydrochlorthiazide; Loop diuretics: furosemide

Explanation

Pirenzepine (selective M₁-cholinoblocker) – decrease gastric secretion. Pancreatine (polyenzyme drug) – increase gastric secretion. Aprotinin (contrycal, gordox) – antitrypsin; antiprotease. Chlorphentermine (desopimonum): appetite suppressant, stimulating CNS.

Explanation

Analeptics (aethimizolum): drugs which act upon the CNS general functions, but stimulate mainly medulla oblongata (respiratory, cardiovascular centers). Aethimizolum acts on the medulla with a direct action.

Aethimizolum also activates the adrenocorticotropic pituitary function which increase cortisol level → ↑production of surfactant. All other options are analeptics but they are only used in the absence of aethimizolum in case of children born with asphyxia.

Lobeline (N-cholinomimetic) can also act as an analeptic but with a reflexive type of action and does not influence the medulla directly. Prazosin (α₁-receptor blocker); Atropine (M-cholinoblocker); Proserin/Neostigmine (cholinomimetic).

Explanation

The symptoms describe cardiac insufficiency. Cardiac glycoside is the most appropriate in this case. Cardiac glycosides are glycosidic drugs of plant origin having cardiac inotropic property, increase myocardial contractility and output. Corglyconum is short acting for acute cardiac insufficiency and administered intravenously.

Digitoxin is long-acting but basically administered orally and used mainly for chronic heart failure (also digoxin).

Cordiamin – analeptic; Adrenaline is commonly used in shocks and coma; Drotaverine – phosphodiesterase 4 inhibitor, antispasmodic (relaxant). Phosphodiesterase 3 inhibitor (nonglycoside cardiotonic)

Explanation

Cholagolics are bile expelling drugs. Their pharmacological effects include: promotes bile excretion and emulsification of fats; absorption of fat and lipid soluble vitamins in intestine, enhance intestinal motor function (intestinal motility).

Explanation

Ochronosis (Alkaptonuria): congenital deficiency of homogentisate oxidase (homogentisic acid oxidase) in the degradative pathway of tyrosine to Fumarate → pigment-forming homogentisic acid accumulates (homogentisuria) in tissues. Autosomal recessive. Usually benign. Urine turns black on prolonged exposure to air. May have debilitating arthralgias (homogentisic acid toxic to cartilage).

Explanation

Narcotic – Opoid. Tussive – Cough.

Glaucine hydrochloride is the only antitussive centrally acting but non-opoid (non-narcotic).

Codeine phosphate and Morphine hydrochloride - antitussive centrally acting but opoid.

Explanation

Benadryl (Diphenhydramine, Dimedrol): Antihistamine (1^st generation) – H₁ receptor blocker. Has sedative, hypnotic and ganglioblocking effects. Loratadine (2^nd generation) – also  an antihistamine but has a weak sedative, hypnotic effect. Prednisolone, Acetylsalicylic acid and Analgin are not antihistamines.

Explanation

* Epinephrine/Adrenaline hydrochloride: is an α-β-adrenergic agonists (adrenomimetics), direct acting. Uses: Anaphylactic shock, hypoglycemic coma…

* Diazepam: Tranquilizer (Benzodiazepine). Uses: anxiety, status epilepticus, night terrors.

* Atropine sulphate: M-cholinoblocker. Uses: eye traumas, GI diseases with ↑acidity.

* Propanolol: β-blocker. Uses: hypertension, Ischemic heart disease.

* Nitroglycerine: Organic nitrates. Uses: angina attack

Explanation

Mebendazole – antihelminthic drug (chemotherapy of nematodes – roundworms). Ascarid eggs are gotten from Ascaris lumbricoides. Other drugs in this group are levamisolum, piperazinum,pyrantel. Nystatin is an antifungal; Chloramphenicol, Tetracycline, Furozolidone are antibiotics.

Explanation

Thymalin is an immunostimulator, it’s the complex of polypeptides fractions of thymus gland of horned cattle. It is a drug of first generation. It stimulate cells immune reactions, restore T lymphocytes quantity and function, correlation of T and B lymphocytes, their subpopulations and increase native killers’ activity, intensify phagocytosis and lymphokines production. It is used in complex therapy of immune deficiency diseases and trophic ulcers.

Explanation

Ketamin is an intravenous anesthesia. It is an antagonist of glutamic acid, blocking the actions of this excitatory transmitter. The drug is a cardiovascular stimulant and this action may lead to an increase in intracranial pressure. Reactions such as disorientation, excitation and hallucinations can occur during recovery from ketamin anesthesia. It has no effect on laryngeal reflexes. Skeletal muscle tone, heart rate, arterial blood pressure and cerebrospinal fluid pressure can be increased by ketamin.

Explanation

Explanation

Lobeline hydrochloride is a N-cholinergic agonists (N-cholinomimetics). It stimulates N-cholinoreceptors located in the CNS, carotid glomerulus, sympathetic and parasympathetic ganglia and adrenal medulla. They are used as respiratory stimulants (analeptics with reflex action) in respiratory arrests.

Atropine sulphate: M-cholinergic antagonist (M-cholinoblocker)

Adrenaline hydrochloride: adrenergic agonist (adrenomimetic)

Mesaton: α-adrenergic agonist (α-adrenomimetic)

Pentamin: ganglioblocker

Explanation

Pyracetam (Nootropil) is a nootropic. Nootropic drugs are drugs which improve cerebral blood flow and optimize energetic metabolism in neurons, increase brain stability in hypoxia, stimulate higher cortical function, memory and education processes. It is administered 20% - 5ml of solution. Craniocerebral trauma is an emergency case; so for fast onset of action, it is administered intravenously. Although, it can also be administered orally or intramuscularly.

Explanation

Aminoglycosides (streptomycini sulfas – 1^st generation; Gentamycini sulfas – 2^nd generation; Amikacin sulfate – 3^rd generation; Arbekacin sulfate - 4th generation). They are protein synthesis inhibitors (antibiotics) and bactericidal. They cause irreversible inhibition of initiation complex through binding of the 30S ribosomal subunit, can also cause misreading of mRNA and also block translocation.

Therapeutic uses include: Pneumonia, chronic urinary tract infections, Tularemia and infections due to Pseudomonas aeruginosa.

Explanation

Panangin is an antidote; a potassium preparation. It is indicated in hypokalemia. It is used to replace potassium concentration in the body. It can also be used as an antiarrhythmic drug.

Explanation

Antipseudomonas penicillins: carbenicillin, ticarcillin, piperacillin – these drugs have activity against several gram negative rods, including Pseudomonas, enterobacter and in some cases Klebsiella species. Carbenicillin-disodium is acid-stable and can be administered orally.

Explanation

Reserpine, a plant alkaloid is a sympatholytic; it blocks the Mg²⁺/adenosine triphosphate-dependent transport of biogenic amines, norepinephrine, dopamine and serotonin from the cytoplasm into storage vesicles in the adrenergic nerves of all body tissues. This causes the ultimate depletion of biogenic amines. Sympathetic function in general is impaired because of decreased release of norepinephrine (↓Arterial pressure). But studies have shown that an appropriate dose of reserpine provokes an increase in output of HCl by the stomach, leading hyperacidity in stomach which is ulcerogenic. Reports of peptic ulceration in individuals receiving reserpine and of increased gastric secretion upon administration of this drug, have engendered the suspicion that reserpine is a significant ulcerogenic agent.

Explanation

Acute poisoning with narcotic analgesics (e.g. morphine) is characterized by sleep or unconsciousness, normal or increased reflexes, normal muscle tone, miosis, bradycardia, cheyne-stokes breath, the retention of urine, a spasm of intestine and bowel. This condition can be treated with:

·        Stomach lavage with 0.5% solution of potassium permanganate.

·        Intravenous injection of Naloxone (naloxone is an antagonist of narcotic analgesic).

·        Atropine; for decrease in the vagal action of morphine.

Explanation

Fluoroquinolones: ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, moxifloxacin. They are all antibiotics. They inhibit prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV.

They are bactericidal and must not be taken with antacids. It is contraindicated in pregnant women, nursing mothers and children

Fluoroquinolones hurt attachments to your Bones.

Explanation

Idiosyncrasy and allergic reaction is as a result of organism’s increased sensitivity to the drugs. It’s a complication of pharmacological therapy (adverse reactions). Tolerance and Tachyphylaxis are effects of repeated doses.

* Idiosyncrasy is genetically conditioned perverse organism’s response to drugs (e.g. inefficiency, lack of enzymes participating in drug metabolism). Genetic deficiency of glucose 6-phosphate dehydrogenase (hereditary enzymopathy). This enzyme is needed for proper functioning of glutathione (an antioxidant) to prevent the oxidative effect of antimalarial drugs on the RBCs.

* Allergic reactions results from antibody production against some drugs.

* Tachyphylaxis is quick weakening of the effect, sometimes may occur after first drug introduction (usually connected with substrate exhaustion).

* Tolerance (habituation): is increasing of the effects in repeated doses resulting from decreasing of absorption, speed-up of the biotransformation or excretion, or decreasing of the receptors sensitivity.

Explanation

Explanation

Abstinence: apart from drugs that are usually recognized as producing dependence, sudden interruption of therapy with certain other drugs also results in adverse consequences, mostly in the form of worsening of the clinical condition for which the drug was being used e.g. Acute adrenal insufficiency may be precipitated by abrupt cessation of corticosteroid therapy; frequency of seizures may increase on sudden withdrawal of an antiepileptic etc. These manifestations are also due to adaptive changes and can be minimized by gradual withdrawal.

Explanation

Vikasol (Menadioni natrii bisulfis) is a synthetic water soluble analogue of Vitamin K.

It’s a coagulant i.e. it prevents hemorrhage (bleeding). It participates in the formation of prothrombin. It promotes normalization of blood clotting. Indications include acute hepatitis, parenchymal and capillary bleeding, obstructive jaundice.

Explanation

Isoniazid is the hydrazide of isonicotinic acid and is a pyridine. Pyridine occurs in many important compounds including  azines and the Vitamins Niacin(B3, NAD) and Pyridoxine(B6). Therefore, isoniazid can be interfered with Vit.B3,B6 and even B1 metabolism by competing with them.

Isoniazid is a first line antituberculosis drug that inhibits the synthesis of mycolic acid. Vit B6 is needed for the transformation of tryptophan to Vit.B3.

Explanation

Acetylcysteine is a synthetic mucolytic (expectorant). It has sulfhydryl group that tear disulfide connections, helps mucosa expelling and reduces the viscosity of mucus. Besides this acetylcysteine is an antioxidant and cardioprotector. It increases bronchial secretion or reduce its viscosity (sputum thinning), facilitating its removal by coughing, they are believed to “loosen” cough which becomes less tiring and more productive.

Explanation

Explanation

Muscarinic receptors belong to the class of G protein-coupled receptors. These receptors, in addition to binding Acetylcholine, it also recognizes muscarine – an alkaloid that is present in certain poisonous mushrooms. Muscarinic effects include miosis, spasm of accommodation, increasing of lacrimal, salivary, gastrointestinal, bronchial and sweat glands secretion, increase of smooth muscle tonus of internal organs, bradycardia, decreased arterial pressure.

Block of M-cholinoreceptor or sympathetic nervous system will produce the opposite effects as described in the question.

Explanation

Sulfonylurea are insulin secretagogues because they promote insulin release from the β-cells of the pancreas. The primary drugs used today are the 2^nd generation drugs – glibenclamide, glipizide, glimepiride etc. These agents are useful in the treatment of patients who have type 2 diabetes mellitus and cannot be managed by diet alone.  Glibenclamide is much more potent and used commonly. 

Explanation

The most common drug used in treating stenocardia is organic nitrates (nitroglycerine). High doses of organic nitrates can cause postural hypotension, facial flushing, tachycardia and headache. Overdose can increase nitrates concentration in blood leading to the formation of methemoglobin with a decreased ability to bind O₂. This results in shortness of breath (respiratory inhibition), cyanosis, mental status changes, fatigue etc.

Explanation

Some commonly observed effects of long-term corticosteroid therapy includes the following:

Osteoporosis is a common adverse effect of long-term corticosteroid therapy, due to the ability of glucocorticoids (prednisolone) to suppress intestinal Ca²⁺ absorption, inhibit bone formation and decrease sex hormone synthesis. Other adverse effects include peptic ulcer (erosions of stomach mucosa), hypokalemia, emotional disturbances and the classic cushing-like syndrome (i.e. redistribution of body fat, puffy face, increased body hair growth, acne, insomnia and increased appetite) are observed when excess corticosteroids are present. Excess corticosteroid results in decreased corticotrophin (adrenocorticotropic hormone) through the negative feedback mechanism.

Explanation

Glucocorticoids have immunosuppressive effects, anti-inflammatory effects, anti-shock, anti-allergic and anti-toxic effects. Immunosuppressive effects: glucocorticoids inhibit some of the mechanisms involved in cell-mediated immunologic functions, especially those dependent on lymphocytes. These agents are actively lymphotoxic and are important in the treatment of hematologic cancers. The drugs do not interfere with the development of normal acquired immunity but delay rejection reactions in patients with organ transplants. This immunosuppressive effect makes the patient susceptible to other infectious diseases (e.g. chronic tonsillitis).

Explanation

Opoids (narcotic analgetic) are natural or synthetic compounds that produce morphine-like effects. All drugs in this category act by binding to specific opoid receptors in the CNS to produce effects that mimic the action of endogenous peptide neurotransmitters (e.g. endorphins, enkephalins and dynorphins). Although the opoids have a broad range of effects, their primary use is to relieve intense pain, whether that pain is from surgery or a result of injury or disease such as cancer.

Explanation

Explanation

Acyclovir is an antiviral drug for herpes and cytomegalovirus infections. The drug is indicated for primary and recurrent mucocutaneous herpes simplex infections in immunocompromised patients. It is also useful in herpes genitalis infections.

Explanation

Type I Hypersensitivity reaction (HSR); anaphylactic and atopic: free antigen cross-links IgE on presensitized (i.e. exposed to the antigen before) mast cells and basophils, triggering immediate release of vasoactive amines that act at postcapillary venules (i.e. histamine). Reaction develops rapidly after antigen exposure because of preformed antibody from first exposure. IgE is the main immunoglobulin involved in type I HSR. Type I: uses IgE and IgG₄

Type I (Immediate, Anaphylaxis, Reagin): IgE (immunoglobulin E)-dependent activation of mast cells/basophils, usually accompanied by eosinophilia e.g. urticaria (hives), hay fever, asthma (wheezing), rhinitis and conjunctivitis (stuffy nose and itchy eyes; usually seasonal)

Explanation

Effect of repeated doses include: accumulation, tolerance (habituation), tachyphylaxis and drug dependence.

            Accumulation is enhancing of the effects in repeated doses that leads to the appearance of toxic effects. 2 types are distinguished:

·        Material accumulation: is accumulation of drug in the manner of bindings with proteins, phospholipids etc.

·        Functional accumulation is accumulation of the drug effect, in spite of its elimination.

The cardiac glycosides are often called digitalis or digitalis glycosides, because most of the drugs come from the digitalis (foxglove) plant. Non-polar glycosides (digitoxin) are fully absorbed and firmly connected with proteins – plasma protein binding 95%. These drugs are accumulated.

Explanation

Potassium permanganate is a non-organic antiseptic and disinfectant. Its an oxidizing agent liberating oxygen, which oxidizes bacterial protoplasm. KMnO₄ → MnO₂ + O₂.

MnO – astringent action; O₂- oxidizing proteins in microbes, deodorizing action, antidote action.

Potassium permanganate is used in disinfections of impaired skin and mucous areas, irrigation of pus wounds.

·        Irrigation of purulent wounds (0.01 – 0.5% solution)

·        Gargling and mouthwash in diseases of throat and oral cavity (0.01 – 0.1% solution)

·        Syringing in gynecology and urology (0.01 – 0.1% solution)

·        Processing of burns (2 – 5% solution)

·        Lavage of stomach in acute poisoning with morphine, alcohol (0.1% solution)

Furacillin: organic antiseptic and disinfectant → furan derivative

Chlorhexidine bigluconate: nonorganic antiseptic and disinfectant → halogen → chlorine containing

Alcoholic iodine solution: nonorganic antiseptic and disinfectant → halogen → iodine containing

Sodium hydrocarbonate: drug for transfusion therapy → drug for correction of acidosis.

Explanation

Intoxication with drugs leads to:

·        Disturbances in organs and systems functions: neurotoxic, hepatotoxic, nephrotoxic, hematotoxic, ulcerogenous – ulcers formation in GIT.

·        Teratogenic: ability to cause fetal malformation (in the first trimester of pregnancy i.e. till 12 weeks.

·        Embryo and fetotoxic: ability to make a toxic influence on embryo and fetus correspondingly, causing disturbance down to death (after 12 weeks).

·        Mutagenic: ability to impact on a genetic level causing mutations in several generations.

·        Blastogenic: ability to cause neoplasms both benign and malignant (carcinogenic).

Mental and physical development lag; fetal alcohol syndrome are fetal malformations.

Explanation

The introduction of an allograft (that is, the graft of an organ or tissue from one individual to another who is not genetically identical) can elicit a damaging immune response, causing rejection of the transplanted tissue. Drugs (immunosuppressors) are now available that more selectively inhibit rejection of transplanted tissues while preventing the patient from becoming immunologically compromised. The principal approach to immunosuppressive therapy is to alter lymphocyte function using drugs or antibodies against immune proteins. Immunosuppressive therapy is also used in the treatment of autoimmune diseases e.g. adrenocorticoids (prednisolone).

Explanation

 Cardiac glycoside is the most appropriate in this case. Cardiac glycosides are glycosidic drugs of plant origin having cardiac inotropic property, increase myocardial contractility and output.

Corglyconum is short acting for acute cardiac insufficiency and administered intravenously.

Digitoxin is long-acting but basically administered orally and used mainly for chronic heart failure (also digoxin).

Explanation

Levodopa is a metabolic precursor of dopamine. It restores dopaminergic neurotransmission in the corpus striatum by enhancing the synthesis of dopamine in the surviving neurons of the substantia nigra. Parkinsonism results from insufficient dopamine in specific regions of the brain, attempts have now been made to replenish the dopamine deficiency. Dopamine itself does not cross the blood-brain barrier, but its immediate precursor (levodopa) is actively transported into the CNS and is converted to dopamine in the brain.

Explanation

Dithylinum is a neuromuscular blocking drug (myorelaxants). It attaches to the N-cholinoreceptor depolarizing the junction and providing a constant stimulation of the receptor. The continued binding of the depolarizing agent renders the receptor incapable of transmitting further impulses. They are used to relax muscles during surgery.

Explanation

Morphine is the major analgesic drug contained in crude opium. Opoids exert their major effects by interacting with opoid receptors in the CNS and in other anatomic structures, such as the GIT and the urinary bladder. Severe respiratory depression can occur and result in death from acute opoid poisoning. A serious effect of the drug is stoppage of respiratory exchange in patients with emphysema or Cor pulmonale. In this case, there is dysregulation of the respiratory center in the CNS.

Explanation

Proserin (neostigmine) is an indirect acting cholinergic agonist (anticholinesterase). It preserves endogenous acetylcholine which can stimulate a greater number of acetylcholine receptors at the muscle endplate. Thereby increasing intestinal peristalsis and tone of urinary bladder.

Dichlothiazide – thiazide diuretic; Reserpine – sympatholytic; Mannitol – Osmotic diuretic; Propanolol – β-adrenoblocker.

Explanation

Abstinence syndrome is renewal or deterioration of the disease after cessation of the drug administration. It is the withdrawal symptoms that occur after abstinence/stoppage of a drug, especially after taking the drug for some relatively long time (e.g. a narcotic).

       Hypertensive crisis is a deterioration of the initial hypertension.

Explanation

Bumetanide, furosemide, torsemide, ethacrynic acid are diuretics that have their major action on the ascending limb of the loop of henle (loop diuretics). These drugs are useful in emergency situation which calls for a rapid, intense dieresis (forced dieresis).

Loop or high-ceiling diuretics inhibit the co-transport of Na⁺/K⁺/2Cl^- on the luminal membrane in the ascending limb of the loop of henle.

Explanation

 Cardiac glycoside is the most appropriate in this case. Cardiac glycosides are glycosidic drugs of plant origin having cardiac inotropic property, increase myocardial contractility and output.

Corglyconum is short acting for acute cardiac insufficiency and administered intravenously.

Digitoxin is long-acting but basically administered orally and used mainly for chronic heart failure (also digoxin).

Explanation

Penicillins inhibit the synthesis of bacterial cell walls and are considered bactericidal too.

They bind penicillin binding proteins (transpeptidases) and block transpeptidase cross-linking of peptidoglycan in cell wall. They also activate autolytic enzymes.

 Benzylpenicillin sodium is a short acting penicillin.

Explanation

The most common complication of insulin therapy is hypoglycemia. For treatment of hypoglycemia:

·        Intravenous injection of glucose solution 500 – 5%

·        Subcutaneous injection of glucagon 1.0ml

·        Subcutaneous injection of 1.0ml – 0.1% adrenaline hydrochloride (epinephrine)

Explanation

All options listed are all opoid analgesics; but Promedol remains the best answer because it has a spasmolytic effect (antispasmodic). Therefore, it is very effective for pains associated with spasms of smooth muscles of internal organs and blood vessels. In comparison with morphine hydrochloride, it has less oppressing activity on respiratory centers, less than excites the center of the vagus nerve and the vomiting center. When the pain is associated with spasms of smooth muscle (angina pectoris, liver, kidney, intestinal cramps) you can assign promedol with atropine, metacin, papaverine etc.

Explanation

Glucocorticoids have immunosuppressive effects, anti-inflammatory effects, anti-shock, anti-allergic and anti-toxic effects. Immunosuppressive effects: glucocorticoids inhibit some of the mechanisms involved in cell-mediated immunologic functions, especially those dependent on lymphocytes. These agents are actively lymphotoxic and are important in the treatment of hematologic cancers. The drugs do not interfere with the development of normal acquired immunity but delay rejection reactions in patients with organ transplants. This immunosuppressive effect makes the patient susceptible to other infectious diseases (e.g. chronic tonsillitis).

Explanation

Glucocorticoids (prednisolone) stimulate gluconeogenesis. As a result, blood sugar rises, muscle protein is catabolized and insulin secretion is stimulated. Corticosteroids cause increased gluconeogenesis, increased lipolysis, CNS effects - at times including euphoria, maintenance of cardiovascular function by potentiation of norepinephrine. Gluconeogenesis uses the reversible reactions from glycolysis and 4 distinct reactions that circumvent the ones from glycolysis that are irreversible. These reactions are catalyzed by pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1, 6-bisphosphatase and glucose-6-phosphatase. Glucagon, epinephrine and glucocorticoids stimulate all these enzymes (excluding pyruvate carboxylase).

Explanation

     Chingamin (chloroquine) prevents polymerization of the hemoglobin breakdown product (heme) into hemozoin.

Intracellular accumulation of heme is toxic to the parasite. It is a weak base and may buffer intracellular pH, thereby inhibiting cellular invasion by parasitic organisms. The drug is solely a blood schizonticide (erythrocytic) and will not eradicate secondary tissue schizonts. It is the drug of choice for acute attacks, prophylaxis and treatment of malaria, has been used in amebic liver disease in combination with metronidazole and in autoimmune disorders including rheumatoid arthritis, systemic lupus erythematous (interstitial disease).

Explanation

All of the benzodiazepines used to treat anxiety (tranquilizers) have some sedative properties and some can produce hypnosis (artificially produced sleep) at higher doses. Their effects have been shown to be mediated by the α₁-GABA_A receptors. Benzodiazepines are the most widely used anxiolytic drugs e.g. Diazepam, lorazepam, nitrazepam, clonazepam etc. They are also used to treat neurosis.

Explanation

     Loratadine is an antihistamine (antiallergic drug) which refers to the classic H₁-receptor blocker. These compounds do not influence the formation or release of histamine. Rather, they block the receptor-mediated response of a target tissue. They are much more effective in preventing symptoms than reversing them once they have occurred. These agents, desloratadine, fexofenadine, and loratadine show the least sedation i.e. least effect on CNS (they don’t induce sleep).

Explanation

Acute poisoning with narcotic analgesics (e.g. morphine) is characterized by sleep or unconsciousness, normal or increased reflexes, normal muscle tone, miosis, bradycardia, cheyne-stokes breath, the retention of urine, a spasm of intestine and bowel. This condition can be treated with:

·        Stomach lavage with 0.5% solution of potassium permanganate.

·        Intravenous injection of Naloxone (naloxone is an antagonist of narcotic analgesic).

·        Atropine; for decrease in the vagal action of morphine.

Explanation

     Several studies, such as the one published in the June 2008 edition of the “Journal of vascular nursing”, have shown reduced levels of vitamin A in patients suffering from leg ulcers, indicating a connection between the two, probably because vitamin A helps to form and maintain healthy skin, mucous membrane and teeth. Vitamin A and the amino acid glutamine help to regenerate healthy epithelial cells.

Explanation

     Doses of bromides have to be determined individually. The bromides are excreted from the organism rather slowly (50-60days), so they may be accumulated and cause the signs of chronic poisoning (bromism). The irritative action of bromides leads to inflammation of the mucous membranes which is accompanied by cough, rhinitis, conjunctivitis and diarrhea.

Explanation

·        Aminazine – neuroleptic (it is better than reserpine for emergency care. It has also proved to be useful in control of intracted hiccup).

·        Diazepam – tranquilizer

·        Sodium bromide – sedative

·        Reserpine – neuroleptic

·        Halothane – general anesthesia

Explanation

     The P450 system is impotant for the metabolism of many endogenous compounds (such as steroids, lipids etc) and for the biotransformation of exogenous substances (xenobiotics). Cytochrome P450, designated as CYP, is a superfamily of heme-containing isozymes that are located in most cells but are primarily found in the liver and GIT. Phase I reactions utilizing the P450 system (also called microsomal mixed function oxidases). The oxidation proceeds by the xenobiotic binding to the oxidized form of cytochrome P450 and then O₂ is introduced through a reductive step, coupled to NADPH: cytochrome P450 oxidoreductase.

Explanation

     Droperidol is often combined with a potent narcotic analgesic such as fentanyl to produce neuroleptanalgesia. It is used for neuroleptanalgesia because of its quick effect (action), short duration of action, myorelaxant and antihypertensive effects. Droperidol has quick and short effects, produces hypotension and myorelaxantia.

         Fentanyl + Droperidol = Talomonal (neuroleptanalgesia)

Explanation

     The cephalosporins are β-lactam antibiotics that are closely related both structurally and functionally to the penicillins. Cephalosporins like the penicillns, inhibit bacterial cell wall synthesis and are considered bactericidal against susceptible organisms.

         Penicillins inhibit the synthesis of bacterial cell walls and are considered bactericidal too. They bind penicillin binding proteins (transpeptidases) and block transpeptidase cross-linking of peptidoglycan in cell wall. They also activate autolytic enzymes.

Explanation

     Loratadine is an antihistamine (antiallergic drug) which refers to the classic H₁-receptor blocker. These compounds do not influence the formation or release of histamine. Rather, they block the receptor-mediated response of a target tissue. They are much more effective in preventing symptoms than reversing them once they have occurred. These agents, desloratadine, fexofenadine, and loratadine show the least sedation i.e. least effect on CNS (they don’t induce sleep).

Explanation

Explanation

Metronidazole forms toxic free radical metabolites in the bacterial cell that damage DNA. It is bactericidal, and an antiprotozoal. It is used to treat Giardia lamblia, Entamoeba histolytica, Trichomonas, Gardnerella vaginalis, Anaerobes (bacteroides, Clostridium difficile). It can be used with a proton pump inhibitor and clarithromycin for “triple therapy” against Helicobacter pylori.

Explanation

Hydrochlorothiazide is a thiazide diuretic. Thiazide diuretics induce hypokalemia and hyperuricemia in 70% of patients and hyperglycemia in 10% of patients.

Serum potassium levels should be monitored closely in patients who are predisposed to cardiac arrhythmias (particularly individuals with left ventricular hypertrophy, ischemic heart disease or chronic heart failure) and those who are concurrently being treated with both thiazide diuretics and digoxin. In general, decreased serum levels of potassium predispose a patient to digoxin toxicity.

Explanation

     Class III antiarrhythmic drugs block potassium (K⁺) channels and thus diminish the outward potassium current during repolarization of cardiac cells. These agents prolong the duration of the action potential without altering phase O of depolarization or the resting membrane potential. Class III drugs include amiodarone, dronedarone, sotalol, dofetilide.

Corglyconum – short acting cardiotonic; it’s a cardiac glycoside (for acute heart failure).

Nitroglycerine – organic nitrate

Dobutamine – β₁ agonist; it’s a nonglycoside cardiotonic

Lisinopril – angiotensin converting enzyme (ACE) inhibitor

Explanation

Muscarinic receptors belong to the class of G protein-coupled receptors. These receptors, in addition to binding Acetylcholine, it also recognizes muscarine – an alkaloid that is present in certain poisonous mushrooms. Muscarinic effects include miosis, spasm of accommodation, increasing of lacrimal, salivary, gastrointestinal, bronchial and sweat glands secretion, increase of smooth muscle tonus of internal organs, bradycardia, decreased arterial pressure.

M-cholinoreceptors increase muscle tonus of internal organs. Therefore blocking this receptor will relieve the bronchospasm.

Explanation

Type I Hypersensitivity reaction (HSR); anaphylactic and atopic: free antigen cross-links IgE on presensitized (i.e. exposed to the antigen before) mast cells and basophils, triggering immediate release of vasoactive amines that act at postcapillary venules (i.e. histamine). Reaction develops rapidly after antigen exposure because of preformed antibody from first exposure. IgE is the main immunoglobulin involved in type I HSR. Type I: uses IgE and IgG₄

Explanation

The nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of chemically dissimilar agents that differ in their antipyretic, analgesic and anti-inflammatory activities. They act primarily by inhibiting the cyclooxygenase (COX 1 and 2) enzymes that catalyze the first step in prostanoid biosynthesis. This leads to a decrease prostaglandin synthesis with both beneficial and unwanted effects. Aspirin is one of the most important NSAID. Its most common side effect is its gastrointestinal (GI) effect. Normally, prostacyclin (PGI₂) inhibits gastric acid secretion, whereas PGE₂ and PGF_2α stimulate synthesis of protective mucus in both the stomach and small intestine.

In the presence of aspirin, these prostanoids are not formed, resulting in increased gastric secretion and diminished mucus protection. This may cause epigastric distress, ulceration, hemorrhage and iron-deficiency anemia.

Celecoxib is a selective cyclooxygenase 2 (COX-2) inhibitor. Approved for treatment of rheumatoid arthritis, osteoarthritis, acute to moderate pain, also approved for patients with peptic ulcers or gastroduodenitis.

Explanation

Heparin is a natural anticoagulant produced in mast cells and basophils. It is an injectable, rapidly acting anticoagulant that is often used acutely to interfere with the formation of thrombi. Heparin is used in the prevention of venous thrombosis and the treatment of a variety of thrombotic diseases such as pulmonary embolism and acute myocardial infarction. Heparin binds to antithrombin III, with the subsequent rapid inactivation of coagulation factors. Antithrombin III inhibits serine proteases, including several of the clotting factors, most importantly, thrombin (factor IIa) and Factor Xa (a-active).

Protamine sulphate antagonizes the anticoagulant effects of heparin. The positively charged protamine interacts with the negatively charged heparin forming a stable complex without anticoagulant activity.

Explanation

     Metoclopramide is an antiemetic drug; an antidopamine. It blocks D₂-dopamine receptors of emetic center in the CNS. It has a central antiemetic effect in vomiting of any genesis. Uses – vomiting induced by irritation of gastrointestinal mucous membrane, post-operative period, pregnancy toxicosis, radiation sickness etc.

Explanation

     Sodium hydrocarbonate/sodium bicarbonate is a systemic alkalinizing agent which when given intravenously will increase plasma bicarbonate, buffer excess hydrogen ion concentration, raise blood pH and reverse the clinical manifestations of acidosis. Sodium bicarbonate is used to increase urinary pH in order to increase the solubility of certain weak acids (e.g cystine, sulphonamides, uric acid) and in the treatment of certain intoxications (e.g. methanol, Phenobarbital, salicylates) to decrease renal reabsorption of the drug or to correct acidosis.

Explanation

Sulfonylurea are insulin secretagogues because they promote insulin release from the β-cells of the pancreas. The primary drugs used today are the 2^nd generation drugs – glibenclamide, glipizide, glimepiride etc. These agents are useful in the treatment of patients who have type 2 diabetes mellitus and cannot be managed by diet alone. Glibenclamide is much more potent and used commonly. 

NB: A 70-year-old patient has greater propensity for type 2 diabetes mellitus.

Explanation

     Chingamin (chloroquine) prevents polymerization of the hemoglobin breakdown product (heme) into hemozoin.

Intracellular accumulation of heme is toxic to the parasite. It is a weak base and may buffer intracellular pH, thereby inhibiting cellular invasion by parasitic organisms. The drug is solely a blood schizonticide (erythrocytic) and will not eradicate secondary tissue schizonts. It is the drug of choice for acute attacks, prophylaxis and treatment of malaria, has been used in amebic liver disease in combination with metronidazole and in autoimmune disorders including rheumatoid arthritis, systemic lupus erythematous (interstitial disease).

Explanation

    Addison’s disease is chronic adrenal insufficiency (hypoaldosteronism). Spironolactone is an aldosterone antagonist. In addison’s disease, there is no aldosterone or it is very low; therefore, spironolactone will not have any effect on such patient.

Explanation

     Non-glycoside cardiotonics includes β₁-adrenergic agonists, phosphodiesterase inhibitors, these drugs prolong synthesis of ATP and have positive inotropic property and increase cardiac output.

Dobutamine – β₁-adrenergic agonists

Caffeine sodium benzoate; Cordiamin; Aethimizolum and Bemegride – Analeptics.

Explanation

Lisinopril is an angiotensin converting enzyme inhibitor (ACE Inhibitor). This drug block the ACE that cleaves angiotensin I to form the potent vasoconstrictor angiotensin II. Rennin converts angiotensinogen to angiotensin I.

Propranolol is a β-blocker; Prazosin – α₁-adrenoblocker; Nifedipine – Ca²⁺-channel blocker; Dichlothiazide – thiazide diuretic.

For a high rate of renin, the antihypertensive drugs that are effective are: renin inhibitor (Aliskiren); angiotensin II receptor blocker and angiotensin converting enzyme (ACE) inhibitors because they block the renin –angiotensin system.

Explanation

Constipations requires the use of laxatives that will stimulate the movement of food through gastrointestinal tract (GIT), produce soft formed stool and accelerate defecation. Bisacodyl is typically prescribed for relief of constipation and for the management of neurogenic bowel dysfunction as well as part of bowel preparation before medical examinations, such as for a colonoscopy. Bisacodyl works directly on the colon to produce bowel movement. It works by stimulating enteric nerves to cause colonic mass movements (contractions); removing the colon hypotonia.

Explanation

Explanation

Angiotensin converting enzyme (ACE) inhibitors block the production of angiotensin II from angiotensin I e.g. Lisinopril, Enalapril

The side effect of this group of drug is dry cough, rash, fever, hypotension, hyperkalemia. Hyperkalemia can cause bradycardia and arrhythmia.

Explanation

Celecoxib is a selective cyclooxygenase 2 (COX-2) inhibitor. Approved for treatment of rheumatoid arthritis, osteoarthritis, acute to moderate pain, also approved for patients with peptic ulcers or gastroduodenitis. Selective COX-2 inhibitors lack disaggregative properties (i.e. they can’t prevent platelet aggregation), unlike non-selective inhibitors of COX-1 and COX-2.

Therefore, there is probability of development of thrombosis when used alone. All other options are non-selective inhibitors of COX-1 and COX-2; which means they have disaggregating properties (especially aspirin).

Explanation

Tranquilizers (anxiolytics) are drugs which reduce state of internal tension, morbid phobia and anxiety, they are used to treat neurosis. Because many tranquilizers also cause some sedation, they can function as both anxiolytic and hypnotic (sleep-inducing) agents, some also have anticonvulsant activity (epileptic seizures). Analeptics (CNS, respiratory stimulants); Neuroleptics (antischizophrenic, antipsychotic); Sedatives (decrease excitement without inducing sleep).

Explanation

Oxytocin is a hormonal drug inducing rhythmic uterine contractions by acting on myometrium cell membranes, increasing their excitability. Oxytocin remains the strongest stimulator of uterine contractions. Estrone is a female sex hormone, but small amounts are also produced in adrenal cortex in both sexes. It’s effects on labour is probably to stimulate cervical ripening through prostaglandin synthesis and not on uterine contraction. The other options are also related to the adrenal gland but no direct effect on uterine contraction.

Explanation

Hydrochlorothiazide is a thiazide diuretic which acts mainly in the distal convoluted tubule to decrease the reabsorption of Na⁺, apparently by inhibition of a Na⁺/Cl^- co-transporter on the luminal surface of the tubules.

Therefore, thiazide diuretics cause diuresis with increase Na⁺ and Cl^-  excretion; Hypochloremic alkalosis results from either low chloride intake or excessive chloride excretion (thiazide diuretics). Low chloride intake (salt-free diet) is very uncommon, excessive chloride excretion often occurs in hospitalized children, usually as a result of diuretic therapy (e.g. thiazide diuretic) or nasogastric tube suctioning.

Explanation

β₂-receptors on the bronchial smooth muscle cause bronchodilation which can relieve the bronchospasm (sympathetic effect).

β₂ adrenergic blockers will increase the bronchospasm and make the patients condition worst.  N-cholinomimetics will have similar effects as β₂ adrenergic blockers. M-anticholinergics (e.g. scopolamine) have dilatory effects but β₂ agonists (e.g. salbutamol, fenoterol, salmoterol) remains the best drugs for relieving bronchoconstriction (bronchospasm) without significant cardiac stimulation unlike M-cholinoblocker which might likely increase cardiac activity by inhibiting vagus effect on heart.

Explanation

Substances that cause food poisoning are xenobiotics, since they are foreign to the body. The body removes xenobiotics by xenobiotic metabolism, which takes place in the liver. Hepatic enzymes (e.g. cytochrome P450) first activate them- phase I (by oxidation, reduction, hydrolysis and/or hydration of the xenobiotic) and then conjugating the active secondary metabolite (phase II) with glucuronic acid, sulphuric acid or glutathione, followed by excretion in bile or urine. Glucuronidation is the most common and the most important conjugation reaction (glucuronidation – conjugation with glucuronic acid).

Explanation

The nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of chemically dissimilar agents that differ in their antipyretic, analgesic and anti-inflammatory activities. They act primarily by inhibiting the cyclooxygenase (COX 1 and 2) enzymes that catalyze the first step in prostanoid biosynthesis.

This leads to decrease prostaglandin synthesis with both beneficial and unwanted effects. Aspirin is one of the most important NSAID. Its most common side effect is its gastrointestinal (GI) effect. Normally, prostacyclin (PGI₂) inhibits gastric acid secretion, whereas PGE₂ and PGF_2α stimulate synthesis of protective mucus in both the stomach and small intestine. In the presence of aspirin, these prostanoids are not formed, resulting in increased gastric secretion and diminished mucus protection. This may cause epigastric distress, ulceration, hemorrhage and iron-deficiency anemia. Analgin is also an NSAID, but aspirin (acetylsalicylic acid) is far more preferable and more common pharmacologically.

Explanation

Heparin is a natural anticoagulant produced in mast cells and basophils. It is an injectable, rapidly acting anticoagulant that is often used acutely to interfere with the formation of thrombi. Heparin is used in the prevention of venous thrombosis and the treatment of a variety of thrombotic diseases such as pulmonary embolism and acute myocardial infarction. Heparin binds to antithrombin III, with the subsequent rapid inactivation of coagulation factors.

Antithrombin III inhibits serine proteases, including several of the clotting factors, most importantly, thrombin (factor IIa) and Factor Xa (a-active).

Protamine sulphate antagonizes the anticoagulant effects of heparin. The positively charged protamine interacts with the negatively charged heparin forming a stable complex without anticoagulant activity.

Explanation

Streptomycin (aminoglycoside) is a 30S ribosomal subunit inhibitor.

Erythromycin (macrolide); Chloramphenicol – 50S subunit inhibitor

Protein synthesis inhibitors specifically target smaller bacterial ribosome (70S –made of 30S and 50S subunits), leaving human ribosome (80S) unaffected. All these drugs block the translation of information on mRNA to protein.

Explanation

Levodopa is a metabolic precursor of dopamine. Because parkinsonism results from insufficient dopamine in specific regions of the brain, attempts have been made to replenish the dopamine deficiency. Dopamine itself does not cross the blood-brain barrier, but its immediate precursor – levodopa, is actively transported into the CNS and is converted to dopamine in the brain. Large doses of levodopa are required, because much of the drug is decarboxylated to dopamine in the periphery, resulting in side effects that include nausea, vomiting, cardiac arrhythmias and hypotension.

Celecoxib: NSAIDs (selective COX-2 inhibitor); indications – rheumatoid arthritis

Droperidol: typical neuroleptic; indications – psychoses, schizophrenia

Chlorpromazine (aminazine): same group and indication as droperidol

Naloxone : opoid antagonist; indications – acute poisoning with narcotic analgesics.

Explanation

All options listed are all opoid analgesics; but Promedol remains the best answer because it has a spasmolytic effect (antispasmodic). Therefore, it is very effective for pains associated with spasms of smooth muscles of internal organs and blood vessels. In comparison with morphine hydrochloride, it has less oppressing activity on respiratory centers, less than excites the center of the vagus nerve and the vomiting center. When the pain is associated with spasms of smooth muscle (angina pectoris, liver, kidney, intestinal cramps) you can assign promedol with atropine, metacin, papaverine etc.

Explanation

K⁺ sparing diuretics:

  - aldosterone antagonist: spironolactone, eplerenone

  - inhibit Na⁺ reabsorption: triamterene

The answer is Spironolactone because after the administration of cardiotonics and a thiazide diuretic, if the edema still persists, it is probably due to an increased action of aldosterone on the principal cells in collecting tubule of the kidney. In this case, an aldosterone antagonist will enhance the diuretic effect to prevent the occurrence of ascites. Blocking aldosterone effect prevent further reabsorption of Na⁺ and H₂O which will definitely enhance the diuretic effect. Aldosterone acts on mineralocorticoid receptor → mRNA → protein synthesis (synthesis of Na⁺ channels). Spironolactone prevents/blocks the synthesis of Na⁺ channels.

Explanation

Analeptics (aethimizolum): drugs which act upon the CNS general functions, but stimulate mainly medulla oblongata (respiratory, cardiovascular centers). Aethimizolum acts on the medulla with a direct action.

Aethimizolum also activates the adrenocorticotropic pituitary function which increase cortisol level → ↑production of surfactant. All other options are analeptics but they are only used in the absence of aethimizolum in case of children born with asphyxia.

Explanation

Explanation

Idiosyncrasy and allergic reaction is as a result of organism’s increased sensitivity to the drugs. It’s a complication of pharmacological therapy (adverse reactions). Tolerance and Tachyphylaxis are effects of repeated doses.

* Idiosyncrasy is genetically conditioned perverse organism’s response to drugs (e.g. inefficiency, lack of enzymes participating in drug metabolism). Genetic deficiency of glucose 6-phosphate dehydrogenase (hereditary enzymopathy). This enzyme is needed for proper functioning of glutathione (an antioxidant) to prevent the oxidative effect of antimalarial drugs on the RBCs.

* Allergic reactions results from antibody production against some drugs.

* Tachyphylaxis is quick weakening of the effect, sometimes may occur after first drug introduction (usually connected with substrate exhaustion).

* Tolerance (habituation): is increasing of the effects in repeated doses resulting from decreasing of absorption, speed-up of the biotransformation or excretion, or decreasing of the receptors sensitivity.

Explanation

The first drug that was found to be capable of blocking the skeletal neuromuscular junction (NMJ) was curare, which native South American hunters of the Amazon region used to paralyze prey. The drug tubocurarine was ultimately purified and introduced into clinical practice in the early 1940s. Muscarinic and Nicotinic receptors are the two cholinergic receptors (cholinoreceptors). Nicotinic receptors are located in the CNS, adrenal medulla, autonomic ganglia and the NMJ. Those at the NMJ are the ones that are blocked by Curariform substances.

Explanation

The described symptoms are for type I diabetes mellitus (especially acetone odor of breath as a result of excess ketone bodies). Type I diabetes mellitus is due to decrease or absent insulin. Insulin facilitates the transport of glucose and amino acids into target organs: In liver – insulin increases the storage of glucose as glycogen. It decreases protein catabolism; In muscles – it stimulates glycogen synthesis and protein synthesis; In Adipose tissue – it facilitates triglyceride storage by activating plasma lipoprotein lipase which increase glucose transport into the cell and by reducing intracellular lipolysis.

Glibenclamide is typically used for type 2 diabetes mellitus.

Adrenaline will further exacerbate the hyperglycemic condition because it stimulates glycogen phosphorylase. Isadrinum is a non-selective β₁-β₂ adrenergic agonists (β-adrenomimetics); it’ll have the same effect as adrenaline. Furosemide is a loop diuretic and will not correct the comatose state of the patient; It has no effect on glucose metabolism or ketone bodies.

Explanation

Allochol and cholenzyme are agents of biliary acids and bile (cholesecretics – induce bile secretion). Cholosas is a plant agent (cholesecretics – induce bile secretion). Nicodinum is a synthetic agent (cholesecretics – induce bile secretion). They all stimulate bile formation. Magnesium sulfate is a drug causing gall bladder contraction and relaxation of sphincter of oddi; it promotes bile excretion. It is also a salt laxative acting on all intestine’s secretions. It is a non-absorbable salt that hold water in the intestine by osmosis and distend the bowel, increasing intestinal activity and producing defecation.

Explanation

Endotoxins: outer cell membrane of most gram negative bacteria. It is not secreted from the cell. It is the structural part of bacteria (lipopolysaccharide) released when the bacteria is lysed. It was originally theorized that endotoxin is released once the bacteria dies. It is now a known fact that bacteria release small amounts of endotoxin as a part of their normal metabolism although the majority is still retained inside the cell. So when the laevomycetin is used, it kills the bacteria but the deterioration of the patient’s condition is as a result of the endotoxin released when the bacteria died. Effects of endotoxin: fever, hypotension, edema, DIC.

Explanation

Hygronium is a ganglioblocker. They can cause dilatation of arteries and veins that leads to an DECREASE of arterial pressure. To normalize Blood pressure (BP), we can use alpha-adrenergic agonists which will cause constriction of smooth muscles in peripheral arterioles.

INCREASE in peripheral resistance will lead to INCREASE BP. Alpha-blockers and Ganglio-blockers will further lead to hypotension. M&N-cholinergic agonist does not have significant effect on BP.

Explanation

Dithyllium is a depolarizing myorelaxant (neuromuscular blocking drug). They are used as adjuvant drugs in anaesthesia during surgery to relax skeletal muscles. An absence or deficiency of acetylcholinesterase/pseudocholinesterase enzyme leads to a silent condition that manifests itself only when people that have the deficiency receive the muscle relaxants.

This enzyme plays an important role in  the metabolism of ester-based local anesthesics, a deficiency of blood cholinesterase can prolong the effect of dithylinium from just 5-7minutes to 8hours.

Explanation

Explanation

One of the major setbacks related to continuous, long term steroid (cortisol, prednisolone). Treatments are symptoms due to changes in the balance of normal hormone secretion. This typically results from taking doses greater than our body’s natural production. Once we begin to decrease or discontinue the dose, however, withdrawal symptoms may occur. Thus, steroids are typically given for the shortest time possible. Short-term use does not induce steroid withdrawal syndrome. In general, the longer you are on this steroid, the longer it is going to take your body to readjust to functioning without it. If you are on it for longer than 2 weeks, it can affect your adrenal glands ability to produce cortisol.

Explanation

Explanation

Sulfonamides inhibit folate synthesis. They also act as antimetabolites of para-amino benzoic acid PABA by inhibiting dihydropteroate synthase.

Explanation

Explanation

Acetylsalicyclic acid (Aspirin) is an NSAID. Cycloxygenase, the enzyme which converts arachidonic acid into the endoperoxide precursors of prostaglandin, has at least two different  isoforms: COX-1 & COX-2. COX-1 is primarily expressed in non-inflammatory cells whereas COX-2 is expressed in activated lymphocytes, polymorphonuclear cells and other inflammatory cells. Acetylsalicyclic acid and the older non-selective NSAIDs inhibit both cyclooxygenase isoforms & thereby decrease prostaglandin & thromboxane synthesis (disaggregating effect) throughout the body.

Explanation

Explanation

Explanation

Isoniazid is the hydrazide of isonicotinic acid and is a pyridine. Pyridine occurs in many important compounds including  azines and the Vitamins Niacin(B3) and Pyridoxine(B6). Therefore, isoniazid can be interfered with Vit.B3, B6 and even B1 metabolism by competing with them.

Isoniazid is a first line antituberculosis drug that inhibits the synthesis of mycolic acid. Vit B6 is needed for the transformation of tryptophan to Vit.B3.

Explanation

 Follicle stimulating hormone and the luteinizing hormone are together called gonadotropic hormones or gonadotropins because of their action on gonads. Products containing a combination of an estrogen and a progestin are the most common type of oral contraceptives. The estrogen provides a negative feedback on the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) by the pituitary gland, thus preventing ovulation. The progestin also inhibits LH release and thickens the cervical mucus, thus hampering the transport of sperm. Oral contraceptives are the drugs taken orally (by mouth) to prevent pregnancy.

Explanation

The adrenal gland (suprarenal gland) has a secretory parenchymal tissue organized into cortical and medullary regions. Adrenal cortex (derived from mesoderm; steroid-secreting portion) and medulla (derived from neural crest; catecholamine-secreting portion). The adrenal cortex is divided into 3 zones on the basis of arrangement of its cells:

* Zona glomerulosa (15%): arranged in closely packed ovoid clusters; secretes aldosterone.

* Zona fasciculata (80%): large and polyhedral; arranged in long straight cords; secretes cortisol.

* Zona reticularis (5-7%): cells are arranged in anastomosing cords separated by fenestrated capillaries; secretes androgens.

Hydrocortisone is a glucocorticoid (cortisol) and an intake of hydrocortisone will decrease endogenous production of cortisol from zona fasciculata of adrenal cortex through feedback inhibition leading to its atrophy.

Explanation

     Cabbage juice is one of the most healing nutrients for ulcer repair as it is a huge source of vitamin U (vitamin U is actually not a vitamin but an enzyme known as S-methylmethionine). Research shows that vitamin U, administered as raw cabbage juice, is effective in promoting the rapid healing of peptic ulcers. Potatoes on the other hand are rich sources of vitamins and minerals. Several studies, such as the one published in the June 2008 edition of the “Journal of vascular nursing”, have shown reduced levels of vitamin A in patients suffering from leg ulcers, indicating a connection between the two, probably because vitamin A helps to form and maintain healthy skin, mucous membrane and teeth. Vitamin A and the amino acid glutamine help to regenerate healthy epithelial cells.

Explanation

     Neostigmine/proserin reversibly inhibits anticholinesterase, an indirect acting cholinergic agonists. It is used symptomatically to treat myasthenia gravis. Proserin does not cause CNS side effects and is not used to overcome toxicity of central acting antimuscarinic agents.

Atropine is an antimuscarinic agent and is used for the treatment of overdoses or intoxication of cholinesterase inhibitor (proserin, physostigmine) and some types of mushroom poisoning (certain mushrooms contain cholinergic substances that block cholinesterases). It also blocks the effects of excess acetylcholine resulting from acetylcholinesterase inhibitors.

Physostigmine and pyridostigmine bromide are acetylcholinesterase inhibitors and will further synergize proserine.

Mesaton is an α-adrenergic agonists (adrenomimetics); Isadrin is a β-adrenergic agonists.

Explanation

     Proserin (Neostigmine) is an indirect acting cholinergic agonist (anticholinesterase). It preserves endogenous acetylcholine which can stimulate a greater number of acetylcholine receptors at the muscle endplate. Halothane, on the other hand, is a general anesthetic that breaks neurotransmission. Proserin stimulates and aids neurotransmission, while halothane breaks neurotransmission (antagonism). This is done indirectly because they don’t act by the same mechanism to antagonize each other. It is functional because each drug weakens the other’s action/effect.

Explanation

     Pharmacokinetics refers to what the body does to a drug. Once a drug is administered through one of several available routes, 4 pharmacokinetic properties determine the speed of onset of drug action, intensity of the drug’s effect and the duration of drug action: absorption, distribution, metabolism and elimination.

Absorption: first, drug absorption from the site of administration permits entry of the therapeutic agent (either directly or indirectly) into plasma. Absorption is the transfer of a drug from its site of administration to the bloodstream via different mechanisms.

Methacycline is a tetracycline. All tetracyclines are adequately absorbed after oral ingestion. However, taking these drugs concomitantly with diary foods in the diet decreases absorption due to the formation of nonabsorbable chelates of the tetracyclines with calcium ions. Nonabsorbable chelates are also formed with other divalent and trivalent cations e.g. those found in magnesium and aluminum antacids and in iron preparations. This presents a problem if a patient self-treats the epigastric upsets caused by tetracycline ingestion with antacids.

Nonforming CO₂ antacids: aluminum hydroxide + magnesium hydroxide = Almagel or Maalox.

Explanation

Metronidazole forms toxic free radical metabolites in the bacterial cell that damage DNA. It is bactericidal, and an antiprotozoal. It is used to treat Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (bacteroides, Clostridium difficile). Entamoeba histolytica causes amebic dysentery.

It can be used with a proton pump inhibitor and clarithromycin for “triple therapy” against Helicobacter pylori.

Explanation

Norepinephrine (noradrenaline), epinephrine (adrenaline) and dopamine are catecholamines produced in chromaffin cells of adrenal medulla from tyrosine.

The catecholamines are inactivated by oxidative deamination catalyzed by monoamine oxidase (MAO) and by O-methylation carried out by Catechol-O-methyltransferase.

The metabolic products of these reactions are excreted in the urine as vanillymandelic acid from epinephrine and norepinephrine; and homovanillic acid from dopamine.

Explanation

Sulfonylurea are insulin secretagogues because they promote insulin release from the β-cells of the pancreas. The primary drugs used today are the 2^nd generation drugs – glibenclamide, glipizide, glimepiride, glibutide etc. These agents are useful in the treatment of patients who have type 2 diabetes mellitus and cannot be managed by diet alone.   Glibenclamide is much more potent and used commonly.

Acarbose – α glucosidase inhibitor.  Actrapid (soluble insulin) is fast acting but not a sulfonylurea.

Explanation

     Certain amino acids undergo decarboxylation that means the removal of their α-carboxyl group resulting in liberation of CO₂ and formation of biogenic amines. Biogenic amines are physiologically active substances such as hormones, neurotransmitters etc. decarboxylation of amino acids:

·        Tryptophan → Niacin → NAD⁺/NADP⁺

Tryptophan → Serotonin →Melatonin

·        Histidine → Histamine

·        Glutamine → GABA

Glutamine → Glutathione

Explanation

Allochol and cholenzyme are agents of biliary acids and bile (cholesecretics – induce bile secretion). Cholosas is a plant agent (cholesecretics – induce bile secretion). Nicodinum is a synthetic agent (cholesecretics – induce bile secretion). They all stimulate bile formation. Magnesium sulfate is a drug causing gall bladder contraction and relaxation of sphincter of oddi; it promotes bile excretion. It is also a salt laxative acting on all intestine’s secretions. It is a non-absorbable salt that hold water in the intestine by osmosis and distend the bowel, increasing intestinal activity and producing defecation.

Explanation

Muscarinic receptors belong to the class of G protein-coupled receptors (parasympathetic nervous system). These receptors, in addition to binding Acetylcholine, it also recognizes muscarine – an alkaloid that is present in certain poisonous mushrooms.

Muscarinic effects include miosis, spasm of accommodation, increasing of lacrimal, salivary, gastrointestinal, bronchial and sweat glands secretion, increase of smooth muscle tonus of internal organs, bradycardia, decreased arterial pressure.

All other options are sympathetic effects (acting through α or β-adrenergic receptors).

Explanation

Nitroglycerine is an organic nitrate. By dephosphorylation of myosin chain; it reduces myocardial contractions → decreased myocardial O₂ consumption; relaxation of vascular smooth muscle → ↑perfusion → improves blood supply to myocardium.

   Administered nitrates → ↑ Nitrites →↑ Nitric oxide (NO) → ↑cGMP → ↑dephosphorylation of myosin chains → vascular smooth muscle relaxation. Nitroglycerin is an organic nitrates. Nitrates inhibit coronary vasoconstriction or spasm, increasing perfusion of the myocardium and thus relieving vasospastic angina. Because of this action, nitrates are effective in treating effort-induced (stress) angina. Classic, effort-induced or stable angina are experienced in such conditions as physical activity, emotional excitement or any other cause of increased cardiac workload.

Explanation

 Promedol remains the best answer because it has a spasmolytic  (antispasmodic) and analgesic effect. Therefore, it is very effective for pains associated with spasms of smooth muscles of internal organs and blood vessels. In comparison with morphine hydrochloride, it has less oppressing activity on respiratory centers, less than excites the center of the vagus nerve and the vomiting center. When the pain is associated with spasms of smooth muscle (angina pectoris, liver, kidney, intestinal cramps) you can assign promedol with atropine, metacin, papaverine etc.

Explanation

Isoniazid is the hydrazide of isonicotinic acid and is a pyridine. Pyridine occurs in many important compounds including  azines and the Vitamins Niacin(B3) and Pyridoxine(B6). Therefore, isoniazid can be interfered with Vit.B3,B6 and even B1 metabolism by competing with them.

Isoniazid is a first line antituberculosis drug that inhibits the synthesis of mycolic acid. Vit B6 is needed for the transformation of tryptophan to Vit.B3.

Explanation

Energy supply to any cell is provided by ATP. Nitroglycerine relieves stenocardia by causing vasodilation thereby increasing blood supply locally to the myocardium.

This increase in blood supply, increases the supply of substrates needed to make ATP. Therefore, a dose of Nitroglycerine → ↑blood supply → ↑substrates for ATP synthesis → ↑intensification of ATP synthesis.

Explanation

Metronidazole forms toxic free radical metabolites in the bacterial cell that damage DNA. It is bactericidal, and an antiprotozoal. It is used to treat Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (bacteroides, Clostridium difficile). It can be used with a proton pump inhibitor and clarithromycin for “triple therapy” against Helicobacter pylori.

Explanation

Aminoglycoside binds the 30S ribosomal subunit and interferes with assembly of the functional ribosomal apparatus and/or can cause the 30S subunit of the completed ribosome to misread the genetic code.

The elderly are particularly susceptible to nephrotoxicity and ototoxicity as an adverse effect of aminoglycosides. Ototoxicity (vestibular and cochlear) is directly related to high peak plasma levels and the duration of treatment. The antibiotic accumulates in the endolymph and perilymph of the inner ear and toxicity correlates with the number of destroyed hair cells in the organ of corti. Deafness may be irreversible and has been known to affect fetuses in utero.

Explanation

Vitamin A is the name given to a group of related compounds that include retinol (vitamin A alcohol); retinal (vitamin A aldehyde) and retinoic acid (vitamin A acid). Rod cells are responsible for dim light vision or night vision or scotopic vision.

Impairment of twilight vision is a defective function of rod cells. Therefore, vitamin A is recommended as the first choice.

Explanation

Magnesium sulfate reduces striated muscle contractions and blocks peripheral neuromuscular transmission by reducing acetylcholine release at the neuromuscular junction. Magnesium is a unique calcium antagonist as it can act on most types of calcium channels in vascular smooth muscle and as such would be expected to decrease intracellular calcium. One major effect of decreased intracellular calcium would be inactivation of calmodulin-dependent myosin light chain kinase activity and decreased contraction, causing arterial relaxation that may subsequently lower peripheral and cerebral vascular resistance, relieve vasospasm and decrease arterial blood pressure. Therefore, it is recommended that intravenous calcium gluconate or calcium chloride should be available as an antagonist of magnesium to increase intracellular calcium level.

Explanation

Acetylsalicyclic acid (Aspirin) is an NSAID.

Cycloxygenase, the enzyme which converts arachidonic acid into the endoperoxide precursors of prostaglandin, has at least two different  isoforms: COX-1 & COX-2. COX-1 is primarily expressed in non-inflammatory cells whereas COX-2 is expressed in activated lymphocytes, polymorphonuclear cells and other inflammatory cells.

Acetylsalicyclic acid and the other non-selective NSAIDs inhibit both cyclooxygenase isoforms & thereby decrease prostaglandin & thromboxane synthesis (disaggregating effect) throughout the body.

Explanation

Muscarinic receptors belong to the class of G protein-coupled receptors of the parasympathetic nervous system. These receptors, in addition to binding Acetylcholine, it also recognizes muscarine – an alkaloid that is present in certain poisonous mushrooms.

Muscarinic effects include miosis, spasm of accommodation, increasing of lacrimal, salivary, gastrointestinal, bronchial and sweat glands secretion, increase of smooth muscle tonus of internal organs, bradycardia, decreased arterial pressure.

All other options are sympathetic effects (acting through α or β-adrenergic receptors).

Explanation

Eubiotics or probiotics aids the development and repopulation of intestinal microbial flora in the event of diarrhea and during treatment with antibiotics and sulfa drugs. A dietary supplement rich in highly concentrated live active cultures contains select high enzymatic function yeast cultures.

Explanation

Morphine is the major analgesic drug contained in crude opium and is the prototype strong agonist. Morphine and several other opoids have high affinity for μ receptors, whereas other agents have varying affinities for δ and κ receptors. Long term chronic administration can result in physical and psychological dependence (addiction). Withdrawal produces a series of autonomic, motor and psychological responses that incapacitate the individual and cause serious (almost unbearable) symptoms. Repeated use produces tolerance to the respiratory depressant, analgesic, euphoric and sedative effects of morphine. Morphinism is excessive or uncontrolled usage of morphine.

Explanation

Natrii valproas (sodium valproate) has antiseizure(antiepileptic) activity. It has proved to be the most effective is seizure states with a subcortical focus (e.g. absence seizures). It has also been effective in grand mal seizures but much less effective in partial seizures. It has anticonvulsant, antidepressant, psychotonic (improves psychic conditions) and cardioprotective effects.

Ethosuxemide and Phenobarbital, phenytoin are antiepileptic but no psychotonic effects. Amitriptyline is an antidepressant.

Explanation

Constipations requires the use of laxatives that will stimulate the movement of food through gastrointestinal tract (GIT), produce soft formed stool and accelerate defecation. Bisacodyl is typically prescribed for relief of constipation and for the management of neurogenic bowel dysfunction as well as part of bowel preparation before medical examinations, such as for a colonoscopy. Bisacodyl works directly on the colon to produce bowel movement. It works by stimulating enteric nerves to cause colonic mass movements (contractions); removing the colon hypotonia.

Explanation

Isoniazid is the hydrazide of isonicotinic acid and is a pyridine. Pyridine occurs in many important compounds including  azines and the Vitamins Niacin(B3) and Pyridoxine(B6). Therefore, isoniazid can be interfered with Vit.B3,B6 and even B1 metabolism by competing with them.

Isoniazid is a first line antituberculosis drug that inhibits the synthesis of mycolic acid. Vit B6 is needed for the transformation of tryptophan to Vit.B3.

The primary adverse effect of isoniazid is peripheral neuritis, manifesting as paresthesias of the hands and feet. This appears to be due to a relative pyridoxine deficiency.

Explanation

     Toxoplasma gondi (a protozoa) causes toxoplasmosis, including congenital toxoplasmosis. Tissue cyst (pseudocysts) in undercooked meat or oocyst in cat faeces infects humans. Stages in human most associated with disease includes:

·        Rapidly multiplying trophozoites (tachyzoites) within various cell types.

·        Tachyzoites can pass placenta and infect fetus (congenital toxoplasmosis)

·        Slowly multiplying trophozoites (bradyzoites) in tissue cysts.

Symptomatic and asymptomatic forms of congenital toxoplasmosis should be treated with a combination of sulfadiazine and pyrimethamine/Trimethoprim. Cotrimoxazole is a combination of sulfadiazine + Trimethoprim

Itraconazole – antifungal; Mebendazole – antihelminthic; Azidothymidine and acyclovir – antiviral.

Explanation

     Barbiturates (Phenobarbital, thiopental) are hypnotics, sedative for anxiety, seizures, insomnia, induction of anesthesia and they induce normal sleep. They have narcotic type of action. Any degree of depression of the CNS is possible, depending on the dose.

Bemegride on the other hand is an analeptic. Analeptics are drugs which act upon the CNS general functions, but stimulates mainly medulla oblongata (respiratory, cardiovascular centers). They can be used in stimulation of respiratory in overdosage or poisoning with narcotic drugs (drugs for general anesthesia, barbiturates).

Both drugs act on CNS but with directly opposite (antagonistic) actions and with a direct action.

Explanation

Hereditary enzymopathy is an inherited inefficiency or lack of enzymes participating in drug metabolism.

Idiosyncrasy and allergic reaction is as a result of organism’s increased sensitivity to the drugs. It’s a complication of pharmacological therapy (adverse reactions). Tolerance and Tachyphylaxis are effects of repeated doses.

* Idiosyncrasy is genetically conditioned perverse organism’s response to drugs (e.g. inefficiency, lack of enzymes participating in drug metabolism). Genetic deficiency of glucose 6-phosphate dehydrogenase (hereditary enzymopathy). This enzyme is needed for proper functioning of glutathione (an antioxidant) to prevent the oxidative effect of antimalarial drugs on the RBCs.

* Allergic reactions results from antibody production against some drugs.

Explanation

Vitamin K-dependent factors include factor II, VII, IX and X; protein C and S. vitamin K is activated in the liver by epoxide reductase.

Activated vitamin K ɣ-carboxylates each of the vitamin K-dependent factors. Carboxylated factors are now able to bind calcium, which are essential for interaction between the coagulation factors and platelet membranes.

Factor II – Prothrombin

Factor VII – Stable factor

Factor IX – Christmas factor

Factor X – Stuart-Prower factor

These factors undergo vitamin K-dependent post-translational modification, whereby a number of their glutamic acid residues are carboxylated to form ɣ-carboxyglutamic acid residues. The ɣ-carboxyglutamyl residues bind calcium ions which are essential for interaction between the coagulation factors and platelet membranes.

Explanation

     Methyluracil is a nonsteroidal anabolic, it can also act as a leucopoiesis stimulator, a non-specific drug which stimulates nucleic acid synthesis and proteins sufficient for leucopoiesis and other regeneration processes. Uses – radiation skin damages, fractures, slow recovering burns, agranulocytosis and leucopenia.

Cyclophosphan and Methotrexate are anticancer drugs (cytostatics)

Prednisolone (glucocorticoids) and cyclosporine are immunosuppressants.

Explanation

     Hypoglycemic coma is an acute condition progressing during rapid reduction of glucose level in blood and abrupt lowering of glucose utilization by brain. Overdosage of insulin is the most common cause; other causes are alcohol, overdose of oral hypoglycemic agents, insulinoma etc.

Treatment: for correction of hypoglycemia

20.0-60.0ml of 40% solution glucose intravenously (IV)

500ml of 5% solution glucose IV drip feed; or

Subcutaneous injection of glucagon 1.0ml

Subcutaneous injection of 1.0ml – 0.1% adrenaline (epinephrine)

Explanation

     The thrombosis in the left coronary artery has probably led to the development of myocardial infarction. Therefore, the best action to take to reestablish blood flow is to break up the thrombus.

To achieve this, we need a fibrinolytic (thrombolytic) – which are used for dissolution of the blood thrombi by stimulating natural fibrinolytic system (activation of plasminogen to active plasmin which degrades fibrin).

Explanation

     Diabetes insipidus (D.I.) is characterized by intense thirst and polyuria (hyperdiuresis) with inability to concentrate urine due to lack of ADH (central D.I.) or failure of response to circulating ADH (nephrogenic D.I.). In central D.I. antidiuretic hormone (ADH) is decreased; in nephrogenic D.I. ADH is normal. Therefore, the hormonal drug we can use to treat diabetes insipidus is to replace the low antidiuretic hormone (ADH) in central diabetes insipidus.

So, we use ADH – a posterior pituitary hormone which increases water reabsorption in renal tubules and decrease diuresis. Its analogue desmopressin acetate can also be administered intranasally. Nephrogenic diabetes insipidus does not require hormonal replacement.

Explanation

     Digitoxin is a long acting cardiac glycoside; used to treat chronic heart failure I-IIB stages, supraventricular tachyarrhythmia (fibrillation, Wolff-Parkinson-White syndrome). Since the patient has been taking this drug in  self-administered doses, there is a high probability of taking an overdosage which can result in toxic concentrations and at toxic concentrations, it causes ectopic ventricular beats that may result in ventricular tachycardia and fibrillation (arrhythmia). This arrhythmia is usually treated with lidocaine or phenytoin but in the absence of this, the first action to take is to stop taking the drug completely (to withhold digitoxin).

Explanation

Dimercaprol (unithiol, British anti-lewisite) is used to chelate mercury, bismuth, arsenic and in combination with edentate calcium disodium to treat lead intoxication. It contains two sulfuhydryl (SH-) groups and forms two bonds with metal ions. Administered intramuscularly.

Explanation

     Antacids are weak bases that react with gastric acid to form water and a salt to diminish gastric acidity. Because pepsin is inactive at a pH greater than 4, antacids also reduce pepsin activity. They can be:

·        CO₂ forming: sodium hydrocarbonate (or carbonate); calcium carbonate

·        Non-forming CO₂: magnesium hydroxide, aluminum hydroxide

Uses: hyperacid gastritis, gastric and duodenal ulcers; poisoning with acids.

Adverse effects: in addition to the potential for systemic alkalosis, sodium hydrocarbonate liberates CO₂ causing belching and flatulence (sensation of stomach swelling); aluminum hydroxide tends to cause constipation, whereas magnesium hydroxide tends to produce diarrhea.

Explanation

Because norepinephrine is the neuromediator of adrenergic nerves, it should theoretically stimulate all types of adrenergic receptors. In practice, when the drug is given in therapeutic doses to humans, the α-adrenergic receptor is most affected.

Norepinephrine causes a rise in peripheral resistance due to intense vasoconstriction of most vascular beds, including the kidney (α₁ effect). Both systolic and diastolic blood pressures increase. α₁ receptors are present on the postsynaptic membrane of the effector organs and mediate constriction of smooth muscle. NB: norepinephrine (noradrenaline) causes greater vasoconstriction than epinephrine, because it does not induce compensatory vasodilation via β₂ receptors on blood vessels supplying skeletal muscles.

Explanation

     Macrolides inhibit protein synthesis by blocking translocation, they bind to the 23S rRNA of the 50S ribosomal subunit. It is bacteriostatic. Examples of macrolides includes azithromycin, clarithromycin, erythromycin etc.

All other options are not macrolides, but are antibiotics.

Ampicillin is an extended spectrum penicillin; a β-lactam antibiotic.

Gentamycin and streptomycin are Aminoglycosides. Together with tetracyclines, they are 30S ribosomal subunit inhibitor.

Explanation

     Etiotropic drug deals directly with the etiological factor (diphtheria toxin). Antidiphtheric antitoxic serum neutralizes the toxin of diphtheria and is employed both as a curative and as a prophylactic agent. Diphtheric anatoxin (diphtheria toxoid) is the diphtheria toxin that has been weakened until it is no longer toxic but is strong enough to induce the formation of antibodies and immunity to the disease.

Explanation

 Indirect anticoagulants:

·        Coumarine derivatives – Neodicumarin, warfarin, syncumar

·        Indandione derivatives – Phenylinum

They antagonize the cofactor functions of vitamin K. Vitamin K is essential for the formation of various clotting factors in the liver, namely clotting factor II, VII, IX and X; Protein C and S.

Factor II – Prothrombin

Factor VII – Stable factor

Factor IX – Christmas factor

Factor X – Stuart-Prower factor

These factors undergo vitamin K-dependent post-translational modification, whereby a number of their glutamic acid residues are carboxylated to form ɣ-carboxyglutamic acid residues. The ɣ-carboxyglutamyl residues bind calcium ions which are essential for interaction between the coagulation factors and platelet membranes. This oral anticoagulants block epoxide reductase and creation of active form of vitamin K resulting in disturbances in prothrombin and proconvertin synthesis in liver.

All other options are not clotting factors.

Explanation

Vitamin P (rutin) – permeability vitamin. They reduce permeability of blood vessels, especially capillaries. It prevents hyaluronic acid (the basic compound of the extracellular matrix) from degeneration by inhibition of the enzyme hyaluronidase. Ascorutin is a drug containing vitamin C and P; it is used to decrease the permeability of blood vessels.

Vitamin C (ascorbic acid): found in fruits and vegetables; an antioxidant; also facilitates iron absorption by reducing it to Fe²⁺ state. It is necessary for hydroxylation of proline and lysine in collagen synthesis; necessary for dopamine β-hydroxylase, which converts dopamine to norepinephrine. Deficiency leads to: scurvy – swollen gums, bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, “corkscrew” hair; Weakened immune response.

Type III collagen is found in blood vessels; Type IV collagen is found in basement membrane. Deficiency in Vitamin C disrupts the second stage of collagen synthesis in fibroblasts (hydroxylation of collagen) which results in petechiae, bruising, hemarthrosis.

Vitamin B₂ (riboflavin) deficiency – growth retardation, glossitis, conjunctivitis

Vitamin B₁ (thiamine) deficiency – Beri-Beri (polyneuritis)

Vitamin A (retinol) deficiency – Night blindness

Vitamin B₉ (folic acid) deficiency – macrocytic megaloblastic anemia

Explanation

Dithyllium is a depolarizing myorelaxant (neuromuscular blocking drug). They are used as adjuvant drugs in anaesthesia during surgery to relax skeletal muscles.

An absence or deficiency of acetylcholinesterase/pseudocholinesterase enzyme leads to a silent condition that manifests itself only when people that have the deficiency receive the muscle relaxants. This enzyme plays an important role in  the metabolism of ester-based local anesthesics, a deficiency of blood cholinesterase can prolong the effect of dithylinium from just 5-7minutes to 8hours.

[Wherever Butyrylcholinesterase occurs in the option along with Acetylcholinesterase; butyrylcholinesterase is the right option in krok]