What medication can affect the metabolism of simvastatin?

• A. Grapefruit juice
• B. Calcium carbonate
• C. Omeprazole
• D. Ibuprofen

Answer: (A)

Grapefruit juice is known to affect the metabolism of simvastatin because it contains compounds called furanocoumarins. These compounds inhibit the cytochrome P450 3A4 enzyme in the liver, which is responsible for the metabolism of simvastatin. When grapefruit juice is consumed, it can lead to increased levels of simvastatin in the bloodstream. This elevation can raise the risk of side effects associated with simvastatin, such as muscle pain or damage. Therefore, it is important for patients taking simvastatin to be cautious about consuming grapefruit juice, as it significantly alters the drug’s pharmacokinetics.

In contrast, the other options listed do not have a significant impact on the metabolism of simvastatin. Calcium carbonate is an antacid that does not interact with the metabolic pathways related to simvastatin. Omeprazole, while it inhibits gastric acid production, does not influence the metabolism of simvastatin. Lastly, ibuprofen, a nonsteroidal anti-inflammatory drug, does not affect the metabolic pathways relevant to simvastatin either. Thus, grapefruit juice stands out as the substance that can substantially influence simvastatin metabolism.