A patient requires a high dose of a new antihypertensive medication because the new medication has a significant first-pass effect. What does this mean?

Correct Answer: C

Rationale: A significant first-pass effect means the medication is extensively metabolized in the liver after oral administration, reducing its bioavailability. This requires a higher dose to achieve therapeutic levels. Choice misinterprets circulation, refers to renal excretion (not first-pass), and suggests tolerance, which isn’t the same phenomenon.

Correct Answer: C

Rationale: The correct answer is C: Premedicate with aspirin. Aspirin can help reduce the flushing side effect of niacin by inhibiting prostaglandin synthesis. This step can help the patient tolerate niacin better without experiencing the redness. Discontinuing the medication (Choice A) is not necessary if the flushing can be managed. Drinking water (Choice B) or taking the medication with food (Choice D) may not effectively address the flushing side effect caused by niacin.

Correct Answer: B

Rationale: The correct answer is B because isotretinoin is known to be highly teratogenic and can cause severe birth defects when taken during pregnancy. This is why it is contraindicated in pregnant women and effective contraception is required before, during, and after treatment. Intravenous administration of isotretinoin is not necessary for the treatment of acne and is typically administered orally. Choice A is incorrect.

Correct Answer: A

Rationale: The correct answer is A: Timing of administration. This is because the timing of administration may influence the pharmacokinetics of the drug but does not necessarily determine the response of the drug itself. Dosage (B), route (C), and frequency (D) are all crucial factors that directly impact the drug's efficacy, safety, and therapeutic effects. Dosage determines the amount of drug reaching the target site, route affects the absorption and distribution of the drug, and frequency determines the duration and intensity of drug action. Therefore, while timing is important for optimal drug effectiveness in some cases, it is not as critical in determining the overall response of a drug compared to dosage, route, and frequency.

Correct Answer: C

Rationale: The correct answer is C: Creatinine clearance. Creatinine clearance is the most accurate indicator of renal function as it directly measures the glomerular filtration rate. Monitoring creatinine clearance helps assess the kidney's ability to filter waste products. Serum creatinine levels (A) can be influenced by factors other than renal function. Serum albumin levels (B) reflect protein status, not renal function. Blood urea nitrogen (BUN) (D) can be affected by factors other than renal function, such as protein intake and liver function. Therefore, creatinine clearance is the best option for monitoring renal excretion in older patients.