Which statement about grapefruit juice and glipizide is true?

Which statement about grapefruit juice and glipizide is true?

• A. There is no drug interaction with grapefruit juice.
• B. Grapefruit juice markedly increases hypoglycemia risk.
• C. Grapefruit juice reduces glipizide absorption.
• D. Grapefruit juice is contraindicated with glipizide.

Answer: (A)

Grapefruit juice affects many drugs by inhibiting intestinal CYP3A4, which can raise the levels of drugs that rely on that enzyme. Glipizide, however, is mainly metabolized in the liver by CYP2C9, with little reliance on intestinal CYP3A4. Because grapefruit juice doesn’t meaningfully alter glipizide’s metabolism or absorption, there’s no clinically relevant interaction and no added risk of hypoglycemia from grapefruit juice alone. The other statements assume a interaction that isn’t supported by how glipizide is processed in the body.

Grapefruit juice affects many drugs by inhibiting intestinal CYP3A4, which can raise the levels of drugs that rely on that enzyme. Glipizide, however, is mainly metabolized in the liver by CYP2C9, with little reliance on intestinal CYP3A4. Because grapefruit juice doesn’t meaningfully alter glipizide’s metabolism or absorption, there’s no clinically relevant interaction and no added risk of hypoglycemia from grapefruit juice alone. The other statements assume a interaction that isn’t supported by how glipizide is processed in the body.