All Free Pharmacology MCQs with Answers

• A. Side effect
• B. Toxicity effect
• C. Idiosyncratic effect
• D. Drug on Drug effect

Explanation: An idiosyncratic effect is an unusual, unpredictable response that is peculiar to an individual and is not explained by the usual…

• A. Morphine
• B. Nitroglycerine
• C. Propranolol
• D. Salicylates

Explanation: Morphine, nitroglycerin and propranolol undergo substantial first-pass metabolism, which reduces their oral bioavailability.

• A. Volume of distribution
• B. Clearance
• C. Rate of administration
• D. Half life

Explanation: Loading dose is determined mainly by the volume of distribution, using the relationship loading dose = target concentration × volume of…

• A. Anti-hypertensives
• B. Anti-diabetics
• C. Anticoagulants
• D. Anti-fibrinolytics

Explanation: Intramuscular injections are avoided in patients receiving anticoagulants because needle trauma can cause painful intramuscular bleeding…

• A. Range of disease in which the drug beneficial
• B. Maximal intensity of response that can be produced by the drug
• C. The therapeutic does range of the drug
• D. The therapeutic index of the drug

Explanation: Efficacy is the greatest response a drug can produce, even when the dose is increased further.

• A. It is the proportion (fraction) of unchanged drug that reaches the systemic circulation
• B. Biovailability of an orally administered drug can be calculated by comparing the area under cure (o-a) after oral and intravenous (IV) administration
• C. Low oral biovailability always and necessarily mean poor absorption
• D. Biovailability can be determined from plasma concentration or urinary excretion data

Explanation: Low oral bioavailability does not necessarily mean poor absorption because extensive first-pass metabolism or chemical degradation can…

• A. Physical dependence
• B. Psychological dependence
• C. Addiction
• D. Habituation

Explanation: Neuroadaptation means compensatory physiological changes produced by continued drug exposure, and these changes underlie physical…

• A. Genetic component
• B. Psychological component
• C. Psysiological component
• D. Nutritional component

Explanation: Idiosyncratic drug reactions are unusual, unpredictable responses that commonly reflect inherited genetic differences in drug metabolism…

• A. Phenytoin
• B. Phenabarbtion
• C. Erythromycin
• D. Digoxin

Explanation: Phenytoin shows capacity-limited metabolism, so its elimination changes from first-order to approximately zero-order as metabolic enzymes…

• A. LD 100/Ed100
• B. ED 100/LD 100
• C. LD 50/ED500
• D. ED50/LD50

Explanation: The therapeutic index is conventionally calculated as LD50 divided by ED50, comparing the median lethal dose with the median effective…

• A. Drugs given IM
• B. Drugs taken orally
• C. Drugs given IV
• D. None of the above

Explanation: Orally administered drugs are absorbed from the gastrointestinal tract and pass through the portal circulation to the liver before…

• A. IgG
• B. IgA
• C. IgM
• D. IgE

Explanation: Secretory immunoglobulin is predominantly IgA, found in saliva, tears, breast milk and mucosal secretions.

• A. Hydolysis
• B. Reduction
• C. Oxidation
• D. Conjugation

Explanation: Phase I reactions expose or introduce functional groups through oxidation, reduction or hydrolysis.

• A. Ranitidine
• B. Sucralfate
• C. Misoprostal
• D. Pantoprazole

Explanation: Ranitidine, misoprostol and pantoprazole suppress gastric acid secretion through H2 blockade, prostaglandin action and proton-pump…

• A. Aminoglycoside
• B. Vancomycin
• C. Calcium channel blocker
• D. Metronidazole

Explanation: Aminoglycosides and vancomycin are renally eliminated and require dose adjustment or monitoring in renal impairment.

• A. H2 antihistamines
• B. NaHCO3
• C. Famotidine
• D. Carbenoxolone

Explanation: Carbenoxolone is a mucosal protective agent that promotes gastric mucus and mucosal defence.

• A. Cimetidine
• B. Famotidine
• C. Ranitidine
• D. All of the above

Explanation: Cimetidine strongly inhibits several hepatic cytochrome P450 enzymes and can raise concentrations of interacting drugs.

• A. Peptic Ulcer
• B. Amoebiasis
• C. Malaria
• D. cholera

Explanation: Omeprazole suppresses gastric acid secretion by irreversibly inhibiting the H+/K+-ATPase in parietal cells, so it is used in peptic ulcer…

• A. Mummifying agent
• B. Anticoagulant
• C. Counter irritant
• D. Anti diarroheal

Explanation: Dolin Pectrose is an antidiarrhoeal preparation, consistent with the pectin-based protective and adsorbent action suggested by its name.

• A. Antihistamine
• B. Proton pump inhibitor
• C. Ulcer protective
• D. Ulcer healing drug

Explanation: Omeprazole is a proton pump inhibitor because it blocks the gastric parietal-cell H+/K+-ATPase, the final step in acid secretion.