A patient who started taking orlistat (Xenical) 1 month ago calls the clinic to report some 'embarrassing' adverse effects. She tells the nurse that she has had episodes of 'not being able to control my bowel movements.' Which statement is true about this situation?

Correct Answer: D

Rationale: The correct answer is D because orlistat works by inhibiting fat absorption. If the patient consumes high-fat meals, it can lead to increased gastrointestinal side effects like fecal incontinence. Therefore, restricting fat intake to less than 30% can help reduce these adverse effects without compromising the drug's efficacy. Choice A is incorrect because these adverse effects are not expected to diminish on their own. Choice B is incorrect as stopping the drug abruptly may not be necessary; rather, adjusting fat intake is a better approach. Choice C is incorrect as increasing fat intake would worsen the gastrointestinal side effects.

Correct Answer: C

Rationale: The correct answer is C: Loop diuretics have a rapid onset of action and cause rapid diuresis. Loop diuretics, such as furosemide, act on the ascending loop of Henle in the kidney to inhibit sodium and chloride reabsorption, leading to increased urine output. This mechanism results in a quick onset of action, typically within 30 minutes of administration, and a rapid diuretic effect. Choice A is incorrect because loop diuretics do not inhibit aldosterone; they primarily target sodium reabsorption. Choice B is incorrect as the duration of diuretic effect varies but is generally shorter than 6 hours. Choice D is incorrect as loop diuretics can still be effective even with reduced creatinine clearance levels.

Correct Answer: D

Rationale: The correct answer is D: “Aranesp is a longer-acting form, so you will receive fewer injections.” Rationale: 1. Darbepoetin (Aranesp) is a longer-acting form of erythropoietin compared to epoetin alfa (Epogen). 2. Due to its extended half-life, Aranesp requires less frequent dosing, leading to fewer injections for the patient. 3. This is beneficial for patient compliance and convenience, as they don't have to undergo frequent injections. 4. Choice A is incorrect because there is a difference between the two drugs in terms of pharmacokinetics. 5. Choice B is incorrect as the speed of action is not the primary difference between the two drugs. 6. Choice C is incorrect because Aranesp, like Epogen, is administered via injections, not orally.

Correct Answer: B

Rationale: The correct answer is B because a competitive antagonist binds to the same receptor site as the agonist, thereby inhibiting the agonist response. This results in a decrease in the efficacy of the agonist without affecting its potency. Choice A is incorrect because a substance producing submaximal effects is a partial agonist, not a competitive antagonist. Choice C is incorrect as competitive antagonists specifically bind to receptor sites, not nonspecific sites. Choice D is incorrect as it describes a partial agonist, which can act as an agonist or antagonist depending on the receptor subtype.

Correct Answer: A

Rationale: The correct answer is A: Bupivacaine. Bupivacaine is more lipid-soluble compared to the other choices. Lipid solubility is an important factor in determining the potency and duration of action of local anesthetics. Bupivacaine has a higher lipid solubility due to its long carbon chain structure, allowing it to penetrate nerve membranes more effectively, resulting in a longer duration of action. Lidocaine, mepivacaine, and procaine are less lipid-soluble and have shorter durations of action compared to bupivacaine. Therefore, bupivacaine is the most lipid-soluble local anesthetic among the choices provided.