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: Isoniazid acts against tuberculosis by inhibiting
A) Protein translation
B) Cell wall cross-linking
C) RNA polymerase
D) Mycolic acid synthesis
✅ Correct Answer: D
Explanation: Isoniazid disrupts mycobacterial cell wall synthesis by blocking mycolic acid production.
Q: Therapeutic use of warfarin is primarily aimed at preventing
A) Hypertension
B) Thromboembolism
C) Hyperglycemia
D) Asthma
✅ Correct Answer: B
Explanation: Warfarin inhibits vitamin K-dependent clotting factors to prevent blood clots.
Q: Furosemide induces diuresis by blocking
A) Na⁺-K⁺-2Cl⁻ symporter
B) Beta receptors
C) Sodium-potassium pump
D) Calcium channels
✅ Correct Answer: A
Explanation: Furosemide acts on the loop of Henle to increase salt and water excretion.
Q: Inhaled corticosteroids are first-line therapy in
A) Asthma
B) Diabetes
C) Anemia
D) Tuberculosis
✅ Correct Answer: A
Explanation: They reduce airway inflammation and prevent asthma exacerbations.
Q: MAO inhibitors elevate mood by preventing
A) Acetylcholine synthesis
B) Dopamine uptake
C) GABA release
D) Monoamine degradation
✅ Correct Answer: D
Explanation: MAOIs block the breakdown of neurotransmitters like serotonin and norepinephrine.
Q: Metronidazole targets anaerobic organisms by damaging
A) Cell membranes
B) DNA structure
C) ATP synthase
D) Protein receptors
✅ Correct Answer: B
Explanation: Metronidazole forms toxic intermediates that bind and fragment DNA.
Q: Haloperidol is classified as a
A) Beta blocker
B) SSRI
C) Typical antipsychotic
D) Diuretic
✅ Correct Answer: C
Explanation: It blocks dopamine receptors to control psychotic symptoms.
Q: Beta-blockers lower blood pressure by reducing
A) Blood sugar
B) Kidney filtration
C) Heart rate
D) Bile secretion
✅ Correct Answer: C
Explanation: These drugs decrease cardiac output and suppress renin release.
Q: The function of naloxone in opioid overdose is to
A) Block histamine
B) Reverse opioid binding
C) Enhance opioid action
D) Stimulate GABA
✅ Correct Answer: B
Explanation: Naloxone is a competitive antagonist at opioid receptors.
Q: First-generation antihistamines often cause
A) Sedation
B) Diarrhea
C) Tachycardia
D) Hypertension
✅ Correct Answer: A
Explanation: Their ability to cross the blood-brain barrier leads to drowsiness.