Indicate the skeletal muscle relaxant, which is a depolarizing agent:

Correct Answer: C

Rationale: Step-by-step rationale: 1. Succinylcholine is a depolarizing agent because it acts as a nicotinic acetylcholine receptor agonist. 2. It causes initial depolarization of the motor end plate leading to muscle fasciculations. 3. By maintaining depolarization, it prevents repolarization and muscle contraction, inducing muscle relaxation. Summary: A. Vecuronium is a non-depolarizing agent that blocks acetylcholine receptors. B. Scopolamine is an anticholinergic drug used for motion sickness. D. Hexamethonium is a ganglionic blocker used for hypertension.

Correct Answer: A

Rationale: Step 1: Identify the key difference between epinephrine and ephedrine - epinephrine is a direct-acting sympathomimetic. Step 2: Ephedrine is a mixed-acting sympathomimetic, acting indirectly by releasing norepinephrine from nerve terminals. Step 3: Therefore, the correct answer is A because ephedrine is not a direct-acting sympathomimetic like epinephrine. Summary: B is incorrect because ephedrine does have oral activity, C is incorrect as ephedrine is not resistant to MAO and has a shorter duration of action, and D is incorrect as ephedrine is less potent than epinephrine.

Correct Answer: A

Rationale: Rationale: Betaxolol is the correct answer as it is a beta1-selective antagonist with a long duration of action due to its lipophilic properties. It has minimal beta2 or intrinsic sympathomimetic activity, leading to prolonged effects on heart rate and blood pressure. Sotalol (B) is a non-selective beta-blocker with class III antiarrhythmic properties. Nadolol (C) is a non-selective beta-blocker with a long duration, but not beta1-selective. Metoprolol (D) is a beta1-selective antagonist but has a shorter duration compared to betaxolol.

Correct Answer: D

Rationale: Step 1: Zolpidem is a sedative-hypnotic medication used for treating insomnia by enhancing the effects of GABA in the brain. Step 2: Zolpidem causes significant effects on sleep patterns, not minor ones, making option A incorrect. Step 3: Zolpidem has a lower risk of tolerance and dependence compared to benzodiazepines, making option B correct. Step 4: Zolpidem primarily acts as a sedative and does not have significant muscle relaxing or anticonvulsant effects, making option C incorrect. Step 5: Combining the above points, option D is correct as it encompasses the accurate statements about zolpidem.

Correct Answer: B

Rationale: The correct answer is B: Valproate. Valproate is contraindicated in patients with hepatic disease because it can cause severe liver damage. Patients with a history of hepatic dysfunction are at higher risk of developing hepatotoxicity with valproate use. A: Lamotrigine is generally safe in patients with hepatic disease and does not have a significant impact on liver function. C: Carbamazepine can also be used cautiously in patients with hepatic disease, although dose adjustments may be necessary. D: Phenytoin is metabolized in the liver, but it is not as strongly associated with liver toxicity as valproate. Therefore, valproate is the correct answer due to its potential for severe hepatotoxicity in patients with hepatic disease or dysfunction.