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: Preferred route for insulin administration
A) Oral
B) Subcutaneous
C) Intravenous
D) Intramuscular
✅ Correct Answer: B
Explanation: Insulin is administered subcutaneously to allow for slow and steady absorption.
Q: Digoxin toxicity is commonly precipitated by
A) Hypernatremia
B) Hypokalemia
C) Hyponatremia
D) Hypercalcemia
✅ Correct Answer: B
Explanation: Low potassium levels increase digoxin binding to cardiac Na⁺/K⁺ ATPase, enhancing toxicity.
Q: Warfarin acts by inhibiting synthesis of
A) Platelets
B) Thrombin
C) Fibrin
D) Vitamin K-dependent clotting factors
✅ Correct Answer: D
Explanation: Warfarin interferes with synthesis of clotting factors II, VII, IX, and X in the liver.
Q: Dopamine precursor used in Parkinson's disease
A) Serotonin
B) GABA
C) Levodopa
D) Acetylcholine
✅ Correct Answer: C
Explanation: Levodopa crosses the blood-brain barrier and is converted to dopamine in the brain.
Q: Preferred inhalational anesthetic for rapid induction
A) Isoflurane
B) Sevoflurane
C) Desflurane
D) Halothane
✅ Correct Answer: C
Explanation: Desflurane has a low blood-gas partition coefficient, leading to fast onset and recovery.
Q: Most common side effect of opioids
A) Cough
B) Constipation
C) Diarrhea
D) Hypertension
✅ Correct Answer: B
Explanation: Opioids decrease gastrointestinal motility, leading to constipation.
Q: Selective serotonin reuptake inhibitor (SSRI) example
A) Phenelzine
B) Amitriptyline
C) Sertraline
D) Imipramine
✅ Correct Answer: C
Explanation: Sertraline increases serotonin levels by inhibiting its reuptake into presynaptic neurons.
Q: Mechanism of action of furosemide
A) Inhibits aldosterone
B) Inhibits carbonic anhydrase
C) Inhibits Na⁺-K⁺-2Cl⁻ transporter in loop of Henle
D) Inhibits Na⁺-Cl⁻ symporter in DCT
✅ Correct Answer: C
Explanation: Furosemide blocks sodium, potassium, and chloride reabsorption in the thick ascending limb.
Q: Antibiotic causing tendon rupture
A) Ciprofloxacin
B) Azithromycin
C) Cephalexin
D) Amoxicillin
✅ Correct Answer: A
Explanation: Fluoroquinolones like ciprofloxacin are associated with tendon damage, especially in elderly patients.
Q: Antidote used for paracetamol overdose
A) Pralidoxime
B) Atropine
C) Flumazenil
D) N-acetylcysteine
✅ Correct Answer: D
Explanation: N-acetylcysteine replenishes glutathione, which detoxifies the harmful metabolite of paracetamol.