Indicate the beta1-selective antagonist:

Correct Answer: B

Rationale: The correct answer is B: Metoprolol. Metoprolol is a beta1-selective antagonist, meaning it selectively blocks beta1-adrenergic receptors. This specificity results in decreased heart rate and contractility without affecting beta2 receptors, which are primarily found in the lungs. Choice A, Propranolol, is a non-selective beta blocker that blocks both beta1 and beta2 receptors. Choice C, Carvedilol, is a non-selective beta blocker with additional alpha-blocking activity. Choice D, Sotalol, is a non-selective beta blocker with Class III antiarrhythmic properties. Therefore, the correct answer is B as it is the only beta1-selective antagonist among the options provided.

Correct Answer: D

Rationale: Step 1: Identify the adverse effects mentioned in the question: Granulocytopenia, gastrointestinal irritation, gingival hyperplasia, and facial hirsutism. Step 2: Recognize the common side effects associated with each drug. Step 3: Phenytoin is known to cause granulocytopenia, gingival hyperplasia, and facial hirsutism. It can also cause gastrointestinal irritation. Step 4: Eliminate other choices: Phenobarbital is not known to cause these side effects. Carbamazepine does not commonly lead to gingival hyperplasia or facial hirsutism. Valproate does not typically cause these specific adverse effects. Step 5: Therefore, the correct answer is D (Phenytoin) as it matches all the mentioned adverse effects.

Correct Answer: B

Rationale: The correct answer is B: Sinemet. Sinemet combines carbidopa and levodopa in a fixed proportion. Carbidopa helps prevent the breakdown of levodopa before it reaches the brain, increasing levodopa's effectiveness. Selegiline (A) is a monoamine oxidase inhibitor, not a combination with carbidopa/levodopa. Tolcapone (C) is a COMT inhibitor, not a combination product. Biperiden (D) is an anticholinergic medication used for Parkinson's disease symptoms but does not contain carbidopa/levodopa.

Correct Answer: C

Rationale: The correct answer is C: Naloxone. Naloxone is a pure opioid antagonist that quickly reverses the effects of opioid overdose by competing for opioid receptor sites. It is used in the treatment of acute opioid overdose to rapidly restore normal respiration and consciousness. Choice A: Pentazocine is a mixed opioid agonist-antagonist and is not used to treat opioid overdose. Choice B: Methadone is a long-acting opioid agonist primarily used for opioid maintenance therapy, not for acute overdose reversal. Choice D: Remifentanil is a short-acting opioid analgesic used during surgery and is not indicated for opioid overdose treatment.

Correct Answer: B

Rationale: The correct answer is B: Benztropine mesylate. Benztropine is an anticholinergic medication that helps alleviate extrapyramidal reactions by blocking excess acetylcholine activity in the brain. Levodopa (A) is used to treat Parkinson's disease but can worsen extrapyramidal reactions. Bromocriptine (C) is a dopamine agonist used in Parkinson's disease, not for treating extrapyramidal reactions directly. Dopamine (D) itself is not used to treat extrapyramidal reactions as it does not directly address the underlying mechanism of the condition.