A patient with depression tells the nurse, 'I don’t think I want to take that SSRI medication the doctor told me she would prescribe. I don’t understand what it will do.' Which of the following would be the most helpful response?

Correct Answer: B

Rationale: The correct answer is B because it provides the patient with a clear and concise explanation of how the medication works to address their depression by correcting a chemical imbalance. This response educates the patient on the purpose of SSRI medications, which helps them understand the potential benefits of treatment. Choice A is incorrect because it oversimplifies the mechanism of action of SSRIs and may not effectively address the patient's concerns. Choice C is incorrect as it focuses more on the general benefits of SSRIs rather than directly addressing the patient's lack of understanding. Choice D is incorrect as it does not provide the patient with the information needed to make an informed decision about medication.

Correct Answer: B

Rationale: The correct answer is B: Acutely decompensated heart failure with dyspnea at rest. Nesiritide (Natrecor) is a medication used specifically for the treatment of acutely decompensated heart failure with dyspnea at rest. This medication helps to reduce cardiac filling pressures and improve symptoms in patients experiencing acute exacerbation of heart failure. Choices A, C, and D are incorrect because nesiritide is not indicated for these conditions. Atrial fibrillation (Choice A) is a cardiac arrhythmia, systolic heart failure (Choice C) involves impaired heart muscle contraction, and long-term treatment of heart failure (Choice D) typically involves different medications like ACE inhibitors, beta-blockers, and diuretics.

Correct Answer: C

Rationale: The correct answer is C because dextromethorphan suppresses the cough reflex by directly acting on the cough center in the brain. This drug inhibits the signals that trigger the cough reflex, leading to reduced coughing. Choice A is incorrect as dextromethorphan does not depress the central nervous system like opioids. Choice B is incorrect because dextromethorphan does not anesthetize stretch receptors. Choice D is incorrect as dextromethorphan does not affect the viscosity of bronchial secretions.

Correct Answer: C

Rationale: The correct answer is C because bioavailability is determined by the extent of absorption and hepatic first-pass effect. Absorption refers to how much of a substance is taken up by the body, while the hepatic first-pass effect is the initial metabolism of a drug in the liver before it reaches systemic circulation. These factors directly impact the amount of a substance that is available to produce its desired effect. Rheological parameters of blood (A) are unrelated to bioavailability. The amount of a substance obtained orally and quantity of intakes (B) may affect bioavailability indirectly but do not determine it. Glomerular filtration rate (D) is related to renal excretion, not bioavailability.

Correct Answer: D

Rationale: The correct answer is D because the ED50 is a measure of potency, not efficacy. Efficacy refers to the maximum effect of a drug, while potency is the comparative measure of the doses needed to produce the same effect. Therefore, A is incorrect because efficacy can be more important clinically than potency in certain situations. B is true as efficacy is indeed the maximum effect of a drug. C is also correct as it accurately describes potency as a comparative measure. In summary, D is incorrect because the ED50 is a measure of potency, not efficacy, making it the exception among the statements provided.