Pharmacology MCQs
Pharmacology MCQs help learners understand the actions, interactions, uses, and side effects of various drugs. These questions cover pharmacokinetics, pharmacodynamics, drug classifications, and toxicology. Practicing them aids in mastering this crucial medical subject and performing well in exams such as MDCAT, USMLE, FCPS, and NTS.
Q: Mechanism of action of aspirin involves
A) Activation of beta-receptors
B) Blocking of dopamine receptors
C) Inhibition of phosphodiesterase
D) Inhibition of cyclooxygenase
✅ Correct Answer: D
Explanation: Aspirin inhibits the cyclooxygenase enzyme, reducing prostaglandin synthesis.
Q: Beta-blockers reduce blood pressure mainly by
A) Increasing cardiac output
B) Reducing renin release
C) Stimulating beta-2 receptors
D) Blocking alpha-receptors
✅ Correct Answer: B
Explanation: Beta-blockers reduce renin secretion, leading to decreased angiotensin II and lower blood pressure.
Q: Drug used as an antidote for heparin overdose
A) Protamine sulfate
B) Atropine
C) Vitamin K
D) Warfarin
✅ Correct Answer: A
Explanation: Protamine sulfate binds to heparin and neutralizes its anticoagulant effect.
Q: Treatment of anaphylactic shock includes
A) Furosemide
B) Diphenhydramine
C) Epinephrine
D) Salbutamol
✅ Correct Answer: C
Explanation: Epinephrine is the first-line treatment due to its vasoconstrictor and bronchodilator properties.
Q: Enzyme inhibited by allopurinol
A) Monoamine oxidase
B) Xanthine oxidase
C) Alcohol dehydrogenase
D) Acetylcholinesterase
✅ Correct Answer: B
Explanation: Allopurinol inhibits xanthine oxidase to reduce uric acid synthesis in gout.
Q: Main neurotransmitter at neuromuscular junction
A) Noradrenaline
B) Acetylcholine
C) Dopamine
D) Serotonin
✅ Correct Answer: B
Explanation: Acetylcholine is released at the neuromuscular junction to trigger muscle contraction.
Q: First-line drug for absence seizures
A) Phenytoin
B) Carbamazepine
C) Ethosuximide
D) Diazepam
✅ Correct Answer: C
Explanation: Ethosuximide selectively inhibits T-type calcium channels in thalamic neurons.
Q: Liver enzyme-inducing antiepileptic drug
A) Levetiracetam
B) Diazepam
C) Phenytoin
D) Valproate
✅ Correct Answer: C
Explanation: Phenytoin induces cytochrome P450 enzymes, altering metabolism of other drugs.
Q: Drug used to reverse benzodiazepine overdose
A) Atropine
B) Naloxone
C) Physostigmine
D) Flumazenil
✅ Correct Answer: D
Explanation: Flumazenil is a benzodiazepine receptor antagonist used for reversal of sedation.
Q: Long-acting insulin preparation
A) Regular insulin
B) Insulin glargine
C) Insulin lispro
D) Insulin aspart
✅ Correct Answer: B
Explanation: Insulin glargine is a long-acting insulin with a flat, prolonged absorption profile.