The nurse notes in a patient’s medical record that nesiritide (Natrecor) has been ordered. Based on this order, the nurse interprets that the patient has which disorder?

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 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.

Correct Answer: A

Rationale: The correct answer is A: Procaine. It is a short-acting drug due to its rapid metabolism by plasma esterases, resulting in a shorter duration of action compared to the other choices. Procaine's quick onset and short duration make it suitable for minor procedures. Tetracaine, Bupivacaine, and Ropivacaine are all long-acting local anesthetics with slower metabolism and longer durations of action, making them more suitable for prolonged surgeries or chronic pain management.

Correct Answer: A

Rationale: The correct answer is A: Hypotension and bradycardia. Nicotine is a stimulant that typically causes hypertension and tachycardia due to its effects on the sympathetic nervous system. Therefore, hypotension and bradycardia are not consistent with the toxic effects of nicotine. Choices B, C, and D are incorrect because convulsions, coma, respiratory arrest, skeletal muscle depolarization blockade, respiratory paralysis, hypertension, and cardiac arrhythmias are all potential toxic effects of a large dose of nicotine due to its impact on various physiological systems.