A patient who has recently started therapy on a statin drug asks the nurse how long it will take until he sees an effect on his serum cholesterol. Which statement would be the nurse’s best response?

Correct Answer: B

Rationale: The correct answer is B: “It takes 6 to 8 weeks to see a change in cholesterol levels.” This is because statins typically take time to reach their full effect on lowering cholesterol levels by inhibiting the enzyme involved in cholesterol production. Within 6 to 8 weeks, the patient can expect to see a significant reduction in their serum cholesterol levels. Choice A is incorrect because blood levels do not return to normal within a week of beginning statin therapy. Choice C is incorrect as it typically does not take 6 months to see a change in cholesterol levels with statins. Choice D is incorrect as significant results can be seen before a year of therapy.

Correct Answer: B

Rationale: Pharmacodynamics refers to how drugs interact with the body to produce their effects, including both desired and undesired effects. Choice B is correct as it specifically mentions information about unwanted effects, which is a key aspect of pharmacodynamics. Choices A, C, and D are incorrect as they do not directly relate to the effects of drugs on the body. Choice A focuses on drug absorption mechanisms, Choice C refers to biological barriers not directly related to drug effects, and Choice D pertains to drug excretion rather than drug action within the body. Therefore, choice B is the most relevant to pharmacodynamics.

Correct Answer: A

Rationale: Local anesthetics are weak bases because they exist mostly in their uncharged form at physiological pH, allowing them to penetrate cell membranes and reach their target site within nerve fibers. The uncharged form can then interact with ion channels to block nerve conduction. Weak acids (choice B) and salts (choice C) are not characteristic of local anesthetics as they do not exhibit the same pharmacological properties needed for nerve blockade. Choice D is incorrect as local anesthetics are indeed weak bases.

Correct Answer: B

Rationale: The correct answer is B: Inhibition of the hydrolysis of endogenous acetylcholine. Indirect-acting cholinomimetic agents work by blocking the enzyme acetylcholinesterase, which breaks down acetylcholine. By inhibiting this enzyme, these agents increase the levels of acetylcholine at the receptor sites, leading to prolonged activation of cholinergic receptors. This mechanism results in enhanced cholinergic effects in the body. Choice A is incorrect because indirect-acting cholinomimetic agents do not directly bind to or activate muscarinic or nicotinic receptors. Choice C is incorrect as these agents do not stimulate the action of acetylcholinesterase; rather, they inhibit its activity. Choice D is incorrect because indirect-acting cholinomimetic agents do not release acetylcholine from storage sites; instead, they prevent its breakdown.

Correct Answer: D

Rationale: The correct answer is D: Respiratory depression. Ganglion blockers were used to treat conditions like hypertension by blocking sympathetic and parasympathetic ganglia. Respiratory depression is not a reason for the disappearance of ganglion blockers. A. Orthostatic hypotension is a common side effect due to extensive blockade of sympathetic ganglia. B. Lack of selectivity leads to non-specific effects on various organ systems. C. Homeostatic reflexes block disrupts normal physiological responses leading to adverse effects. Overall, respiratory depression is not a prominent reason for the decline in the use of ganglion blockers compared to the other listed reasons.