Grapefruit juice should be avoided with which antihypertensive class due to an interaction?

Grapefruit juice should be avoided with which antihypertensive class due to an interaction?

• A. Calcium channel blockers
• B. ACE inhibitors
• C. ARBs
• D. Beta blockers

Answer: (A)

Grapefruit juice interacts with certain drugs by blocking an intestinal enzyme called CYP3A4, which normally metabolizes many medications as they’re absorbed. When this enzyme is inhibited, the drug isn’t broken down as quickly, so more of it enters the bloodstream and the effect lasts longer. Calcium channel blockers—especially the dihydropyridine-type agents used for hypertension—are commonly affected by this interaction, so grapefruit juice can markedly increase their blood levels and enhance both the therapeutic effect and the risk of side effects like excessive lowering of blood pressure and dizziness. ACE inhibitors, ARBs, and beta blockers are not primarily processed by intestinal CYP3A4 in a way that causes a meaningful grapefruit interaction, so grapefruit juice isn’t a major concern with those classes. That’s why the calcium channel blocker class is the one to avoid with grapefruit juice.

Grapefruit juice interacts with certain drugs by blocking an intestinal enzyme called CYP3A4, which normally metabolizes many medications as they’re absorbed. When this enzyme is inhibited, the drug isn’t broken down as quickly, so more of it enters the bloodstream and the effect lasts longer. Calcium channel blockers—especially the dihydropyridine-type agents used for hypertension—are commonly affected by this interaction, so grapefruit juice can markedly increase their blood levels and enhance both the therapeutic effect and the risk of side effects like excessive lowering of blood pressure and dizziness.

ACE inhibitors, ARBs, and beta blockers are not primarily processed by intestinal CYP3A4 in a way that causes a meaningful grapefruit interaction, so grapefruit juice isn’t a major concern with those classes. That’s why the calcium channel blocker class is the one to avoid with grapefruit juice.