Answer: A. Sulphonylureas

Explanation: Sulphonylureas potentiate the action of insulin by stimulating the release of insulin from pancreatic beta cells, thereby enhancing its blood glucose-lowering effect in patients with type 2 diabetes.

Answer: B. Antagonist of ER

Explanation: Tamoxifen is a selective estrogen receptor modulator (SERM) that acts primarily as an antagonist on estrogen receptors in breast tissue, thereby inhibiting the growth of estrogen receptor–positive breast cancers.

Answer: B. Vitamin B

Explanation: Isoniazid therapy is associated with vitamin B6 (pyridoxine) deficiency; therefore, vitamin B supplementation is prescribed concurrently to prevent peripheral neuropathy and other adverse effects.

Answer: B. Epilepsy

Explanation: Levetiracetam is an anticonvulsant used primarily to control seizures in patients with epilepsy. It works by modulating synaptic neurotransmitter release and stabilizing neuronal activity in the brain.

Answer: D. Ethambutol

Explanation: Ethambutol inhibits arabinosyltransferase, an enzyme crucial for the synthesis of mycobacterial cell wall components, making it effective in the treatment of tuberculosis by disrupting cell wall assembly.

Answer: A. Diethylstilbestrol

Explanation: Exposure to diethylstilbestrol (DES) in utero is linked to a higher risk of vaginal carcinoma in female offspring. This synthetic estrogen has been shown to disrupt normal hormonal development.

Answer: C. Labetalol

Explanation: Labetalol blocks both α and β receptors, making it effective in reducing blood pressure by decreasing heart rate and dilating blood vessels. This dual antagonism distinguishes it from agents that selectively block one receptor type.

Answer: C. Belladonna

Explanation: Pinpoint pupils are caused by opioids (morphine) or organophosphates, not belladonna (causes mydriasis).

Answer: D. All of the above

Explanation: Glucocorticoids, β-blockers, and thiazide diuretics can all contribute to secondary hyperlipidemia by altering lipid metabolism and increasing serum cholesterol and triglyceride levels.

Answer: A. 1,2-Dihydropyridine

Explanation: Nifedipine is a 1,4-dihydropyridine. Correct answer is C.

Answer: D. Mode of action

Explanation: Prodrugs are designed to improve the delivery of the active drug, but once converted, they exhibit the same mode of action as the parent drug. Their differences lie in absorption, distribution, or metabolism, not in the mechanism of action.

Answer: A. Lesinurad

Explanation: Lesinurad inhibits the renal urate transporter, increasing uric acid excretion and reducing serum uric acid levels. This mechanism makes it effective as an antigout drug when used in combination therapy.

Answer: B. Triptan

Explanation: Triptans are selective 5-HT1 receptor agonists used as first-line therapy for acute migraine attacks. They relieve headache symptoms by constricting cranial blood vessels and inhibiting neuropeptide release.

Answer: D. Chloramphenicol

Explanation: Chloramphenicol is produced by chemical synthesis rather than fermentation. Its synthetic production allows for consistent quality and supply for its use as a broad-spectrum antibiotic.

Answer: C. Vancomycin

Explanation: Red man syndrome is an infusion-related reaction characterized by flushing and rash. It is most commonly associated with vancomycin administration, due to histamine release during rapid infusion.

Answer: C. Cyclophosphamide

Explanation: Mesna is administered with cyclophosphamide to prevent hemorrhagic cystitis by neutralizing the toxic metabolites. It acts as a protective agent in chemotherapy regimens to reduce side effects.

Answer: D. Ethambutol

Explanation: Ethambutol is known to cause optic neuropathy, which can lead to vision impairment. This adverse effect requires regular ophthalmologic monitoring during treatment for tuberculosis.

Answer: D. Lead

Explanation: A 'lead' compound in drug discovery is a molecule that shows promise in preliminary tests for its biological activity and possesses properties that can be optimized further to develop an effective drug.

Answer: A. Cangrelor

Explanation: Cangrelor is an intravenous antiplatelet agent that received US FDA approval in 2015. It acts rapidly by blocking the P2Y12 receptor on platelets, reducing the risk of thrombotic events during acute cardiovascular interventions.

Answer: A. Zaleplon

Explanation: Zaleplon is a non-benzodiazepine hypnotic agent that acts as an agonist at the benzodiazepine receptor. It is used primarily for the short-term treatment of insomnia due to its rapid onset and short duration of action.