Correct Answer: D

Rationale: The correct answer is D. Sildenafil (Viagra) should not be taken with nitrates due to the risk of severe hypotension. Nitrates can potentiate the hypotensive effects of sildenafil, leading to a dangerous drop in blood pressure. Choice A is incorrect because sudden hearing loss is a rare but serious side effect associated with sildenafil, not a common side effect. Choice B is not the most important information related to sildenafil use. While it is generally recommended not to exceed one dose per day, the interaction with nitrates is more critical. Choice C is also important to consider as high-fat meals can delay the onset of action of sildenafil, but it is not as crucial as avoiding nitrates.

Correct Answer: B

Rationale: In patients with chronic renal failure, especially in older adults, dosages of medications excreted renally need to be adjusted based on kidney function. Acyclovir is primarily eliminated by the kidneys, so in a patient with chronic renal failure, the dose would need to be smaller to prevent drug accumulation and toxicity. Choice A is incorrect because the dose adjustment is more related to the patient's kidney function than the presence of herpes simplex. Choice C is incorrect because the type of herpes infection does not determine the dose adjustment for acyclovir. Choice D is incorrect as the creatinine clearance is a more accurate measure of kidney function compared to creatinine levels.

Correct Answer: C

Rationale: The correct answer is C: Special visceral afferent cells. These cells are responsible for innervating taste and smell receptors related to the gut. Special somatic afferent fibers (choice A) are involved in sensations like touch and proprioception, not taste and smell. General somatic afferents (choice B) carry sensory information from the skin and musculoskeletal system, not taste and smell. General visceral afferent neurons (choice D) transmit sensory information from internal organs, but not specifically related to taste and smell sensations.

Correct Answer: C

Rationale: After the administration of interferon alfa-2b, the patient may develop flu-like symptoms as an adverse effect. Flu-like symptoms are commonly associated with interferon therapy, including fever, chills, fatigue, and muscle aches. These symptoms usually subside over time. Options A, B, and D are not typically associated with interferon alfa-2b administration. Profound diaphoresis is excessive sweating, decreased level of consciousness indicates neurological issues, and cyanosis and pallor suggest circulatory or respiratory problems, none of which are expected adverse effects of interferon alfa-2b.

Correct Answer: A

Rationale: The correct answer is A: Use of nitrates. Sildenafil (Viagra) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both cause vasodilation, so their combined use can lead to a dangerous drop in blood pressure. Choices B, C, and D are incorrect because while a history of hypertension or use of antihypertensive medications may influence treatment decisions, they are not the key contraindication specifically related to sildenafil use.