A patient who has been taking antihypertensive drugs for a few months complains of having a persistent dry cough. The nurse knows that this cough is an adverse effect of which class of antihypertensive drugs?

Correct Answer: B

Rationale: The correct answer is B: Angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors can cause a persistent dry cough as an adverse effect due to the accumulation of bradykinin, a substance that causes coughing. Other choices are incorrect because: A: Beta blockers are not known to cause persistent dry cough. C: Angiotensin II receptor blockers (ARBs) are less likely to cause cough compared to ACE inhibitors. D: Calcium channel blockers are not associated with causing a dry cough.

Correct Answer: C

Rationale: The correct answer is C: phenytoin (Dilantin) has a significant drug interaction with isoniazid. Phenytoin is a substrate of the enzyme CYP2C9, which is inhibited by isoniazid, leading to increased phenytoin levels and potential toxicity. Pyridoxine (A) is often given with isoniazid to prevent peripheral neuropathy. Penicillins (B) do not have significant interactions with isoniazid. Benzodiazepines (D) are not metabolized through CYP2C9 and therefore do not interact significantly with isoniazid.

Correct Answer: B

Rationale: Correct Answer: B (FALSE) Rationale: 1. Metabolic transformation and conjugation often lead to the inactivation or reduction of a substance's biological activity. 2. Conjugation typically involves adding a polar group to increase the substance's water solubility for excretion. 3. Metabolic transformations can lead to the formation of less active or inactive metabolites. 4. Therefore, the correct answer is FALSE as these processes usually decrease the biological activity of a substance. Summary: - Choice A (TRUE) is incorrect as metabolic transformation and conjugation generally decrease, not increase, a substance's biological activity. - Choice C (All) and Choice D (None) are also incorrect as the correct answer is specifically B, indicating a decrease in biological activity.

Correct Answer: A

Rationale: The correct answer is A: Intermediate chain. The duration of local anesthetic action is mainly determined by the intermediate chain in the structure. The length and structure of the intermediate chain influence the rate of diffusion through tissues and the binding affinity to sodium channels. Lipophilic and ionizable groups do play a role in the mechanism of action of local anesthetics but do not directly affect the duration of action. Therefore, choice A is the most relevant in determining the duration of local anesthetic action compared to the other choices.

Correct Answer: B

Rationale: The correct answer is B because carbachol causes miosis (pupillary constriction) instead of mydriasis (pupillary dilation). Carbachol stimulates muscarinic receptors causing constriction of the pupil. Choices A, C, and D are incorrect because carbachol does decrease intraocular pressure, exerts both nicotinic and muscarinic effects, and is resistant to acetylcholinesterase, respectively.