NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Which medications increase when taken with strong CYP3A4 inhibitors?

1. Metformin, glipizide, and glimepiride

2. Lovastatin, simvastatin, and atorvastatin

3. Lisinopril, amlodipine, and losartan

4. Hydrochlorothiazide, furosemide, and spironolactone

The correct answer is: Lovastatin, simvastatin, and atorvastatin

Strong CYP3A4 inhibitors can increase the serum levels of medications that are substrates of this enzyme due to inhibition of their metabolism. Lovastatin, simvastatin, and atorvastatin are all statins that are metabolized by CYP3A4. When taken with strong CYP3A4 inhibitors, such as certain antifungals or protease inhibitors, these statins can accumulate in the body, potentially leading to increased risk of statin-related adverse effects, such as myopathy and rhabdomyolysis. Therefore, it is important to monitor patients taking these statins when co-administered with strong CYP3A4 inhibitors. The other options (A, C, and D) do not include medications that are known substrates of CYP3A4, making them less likely to be affected by strong CYP3A4 inhibitors in the same manner as statins.