Which of the following agents is a ganglion-blocking drug?

Correct Answer: B

Rationale: The correct answer is B: Hexamethonium. Ganglion-blocking drugs act by blocking nicotinic receptors in autonomic ganglia, leading to decreased sympathetic and parasympathetic responses. Hexamethonium is a ganglion-blocking drug that specifically acts on ganglionic nicotinic receptors. - A: Homatropine is a muscarinic antagonist used to dilate the pupil. - C: Rapacuronium is a non-depolarizing neuromuscular blocking agent. - D: Edrophonium is an acetylcholinesterase inhibitor used for the diagnosis of myasthenia gravis.

Correct Answer: B

Rationale: The correct answer is B: Bronchodilation. Ephedrine is a sympathomimetic amine that acts on alpha and beta adrenergic receptors. It primarily stimulates beta-2 adrenergic receptors in the lungs, leading to bronchodilation. This action helps in the treatment of asthma and other respiratory conditions. Miosis (choice A) is constriction of the pupil, which is not a known effect of ephedrine. Hypotension (choice C) is low blood pressure, but ephedrine is more likely to cause hypertension due to its vasoconstrictive effects. Bradycardia (choice D) is a slow heart rate, but ephedrine usually causes tachycardia due to its stimulatory effects on the heart.

Correct Answer: C

Rationale: The correct answer is C: Nadolol. Nadolol is a non-selective beta blocker with a long half-life, leading to an extended duration of action. It is typically dosed once daily, making it convenient for patients. Metoprolol (A) and Propranolol (B) have shorter durations of action compared to Nadolol. Pindolol (D) is a partial beta agonist and does not exhibit a long duration of action like Nadolol.

Correct Answer: B

Rationale: The correct answer is B: Zolpidem. Zolpidem is a hypnotic drug that selectively binds to the BZ1 receptor subtype, which enhances the inhibitory function of the neurotransmitter GABA. This specific binding to the BZ1 receptor subtype results in sedative and hypnotic effects without significant anxiolytic or muscle relaxant properties. Incorrect Choices: A: Thiopental - Thiopental is a barbiturate that acts on GABA receptors but does not selectively bind to the BZ1 receptor subtype. C: Flurazepam - Flurazepam is a benzodiazepine that primarily acts on the BZ2 receptor subtype, not the BZ1 receptor subtype. D: Phenobarbital - Phenobarbital is a barbiturate that enhances GABAergic transmission but does not selectively bind to the BZ1 receptor subtype. In summary, Zolpidem is the correct answer because it specifically targets the

Correct Answer: A

Rationale: The correct answer is A: Topiramate. Topiramate is known for its high risk of causing cognitive side effects, such as memory impairment and confusion, due to its mechanism of action on neurotransmitters. Phenytoin (B), Valproate (C), and Gabapentin (D) are less likely to cause significant cognitive side effects compared to Topiramate. Phenytoin is more associated with motor coordination issues, Valproate with weight gain and liver toxicity, and Gabapentin with sedation and dizziness. Therefore, based on the pharmacological profile of each drug, Topiramate stands out as the drug with a high risk of cognitive side effects.