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: Adverse effect commonly associated with aminoglycosides
A) Ototoxicity
B) Hepatotoxicity
C) Hyperkalemia
D) Bone marrow suppression
✅ Correct Answer: A
Explanation: Aminoglycosides can cause irreversible damage to the auditory and vestibular systems.
Q: Primary action of loop diuretics
A) Aldosterone receptor blockade
B) Inhibition of Na⁺-K⁺-2Cl⁻ transporter in thick ascending limb
C) Sodium reabsorption in distal tubule
D) Inhibition of carbonic anhydrase
✅ Correct Answer: B
Explanation: Loop diuretics act on the thick ascending limb to block sodium and chloride reabsorption.
Q: Pharmacological classification of omeprazole
A) Antacid
B) H2 blocker
C) Prokinetic agent
D) Proton pump inhibitor
✅ Correct Answer: D
Explanation: Omeprazole irreversibly inhibits the H⁺/K⁺ ATPase pump in gastric parietal cells.
Q: Use of atropine in organophosphate poisoning
A) Activates muscarinic receptors
B) Blocks muscarinic receptors
C) Stimulates nicotinic receptors
D) Enhances acetylcholine
✅ Correct Answer: B
Explanation: Atropine blocks overstimulated muscarinic receptors caused by excess acetylcholine.
Q: Drug of choice for status epilepticus
A) Carbamazepine
B) Diazepam
C) Ethosuximide
D) Lamotrigine
✅ Correct Answer: B
Explanation: Diazepam, a benzodiazepine, is rapidly effective in controlling convulsions.
Q: Therapeutic use of methotrexate
A) Parkinsonism
B) Rheumatoid arthritis
C) Hyperthyroidism
D) Diabetes mellitus
✅ Correct Answer: B
Explanation: Methotrexate is used in low doses to suppress immune activity in autoimmune diseases.
Q: Cisplatin is most toxic to the
A) Bone marrow
B) Kidneys
C) Liver
D) Lungs
✅ Correct Answer: B
Explanation: Nephrotoxicity is the dose-limiting adverse effect of cisplatin.
Q: Drug used to treat bradycardia
A) Digoxin
B) Labetalol
C) Propranolol
D) Atropine
✅ Correct Answer: D
Explanation: Atropine blocks vagal stimulation, increasing heart rate.
Q: Mechanism of action of sulfonamides
A) Inhibit DNA gyrase
B) Bind ribosomal subunit
C) Inhibit cell wall synthesis
D) Block folic acid synthesis
✅ Correct Answer: D
Explanation: Sulfonamides competitively inhibit dihydropteroate synthase, blocking folate production.
Q: Adverse effect of chronic corticosteroid therapy
A) Hyperkalemia
B) Bradycardia
C) Osteoporosis
D) Hypoglycemia
✅ Correct Answer: C
Explanation: Long-term corticosteroid use leads to bone resorption and osteoporosis.