Correct Answer: C

Rationale: The correct response is to remind the patient that antiretroviral drugs are most effective when taken consistently and as prescribed. Choice A is incorrect because taking a double dose after missing a dose is not recommended, as it can lead to medication toxicity. Choice B is incorrect as it may give the impression that missing doses is acceptable, which can reduce the effectiveness of the treatment. Choice D is incorrect because while consistency is important, the focus should be on treatment effectiveness rather than side effects.

Correct Answer: A

Rationale: The correct answer is A: Increased risk of venous thromboembolism. Tamoxifen is known to increase the risk of venous thromboembolism, a serious side effect. Patients should be educated about the signs and symptoms of blood clots such as swelling, redness, warmth, or pain in the affected limb. Choices B, C, and D are incorrect because tamoxifen is not associated with an increased risk of hot flashes, cataracts, or bone fractures.

Correct Answer: B

Rationale: Metaplasia is the replacement of one type of cell with another, which can occur in response to chronic irritation, such as from smoking. In this case, the respiratory tract cells being replaced by less mature squamous epithelium cells indicate metaplasia. Dysplasia refers to abnormal development or growth of cells, not replacement; hyperplasia is an increase in the number of cells, not a replacement; and coagulation is a process related to blood clotting, not cell replacement.

Correct Answer: B

Rationale: The correct answer is B: 'Do not take more than one dose in a 24-hour period.' It is essential for the nurse to emphasize this instruction to prevent potential adverse effects from taking multiple doses of sildenafil. Choice A is incorrect because sildenafil should be taken approximately 30 minutes to 4 hours before sexual activity, not specifically 1 hour before. Choice C is important but not the priority; while vision or hearing loss are potential serious side effects of sildenafil, the immediate concern should be focused on dose frequency. Choice D is incorrect as sildenafil can be taken with or without food.

Correct Answer: C

Rationale: When GABA binds with a receptor site, it causes hyperpolarization of the local nerve membrane, making it less excitable. This hyperpolarization leads to inhibition of nerve cell activity. Choice A is incorrect because GABA is a neurotransmitter itself and does not require three chemical substances to stimulate activity between cells. Choice B is incorrect as GABA triggers inhibitory postsynaptic potentials (IPSPs), leading to hyperpolarization, not depolarization, of the postsynaptic membrane. Choice D is also incorrect as it describes a process involving cholinergic receptors and acetylcholine, which is unrelated to GABA's mechanism of action.