A relatively pure alfa agonist causes all of the following effects EXCEPT:

Correct Answer: C

Rationale: The correct answer is C because a relatively pure alpha agonist primarily acts on alpha receptors in blood vessels causing vasoconstriction, leading to increased peripheral arterial resistance and reflex bradycardia. This results in an increase in blood pressure and venous return. Since alpha agonists primarily target blood vessels, they do not have a direct effect on blood vessels. Choices A, B, and D are incorrect as they are known effects of alpha agonists.

Correct Answer: C

Rationale: Thiopental is the correct answer because it is an ultra-short-acting barbiturate with a rapid onset and short duration of action. It is commonly used for induction of anesthesia due to its fast-acting properties. Secobarbital and Amobarbital are short to intermediate-acting barbiturates, while Phenobarbital is a long-acting barbiturate used for seizure control. In summary, Thiopental stands out as the ultra-short-acting option compared to the other choices due to its specific pharmacokinetic profile.

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.