Which drug interaction with methotrexate is demonstrated by the material?

• A. Ibuprofen
• B. Vitamin C
• C. Paracetamol
• D. Omeprazole

Answer: (D)

The main idea is that methotrexate is cleared by the kidneys, so anything that reduces its renal elimination can raise methotrexate levels and increase toxicity. Omeprazole, a proton pump inhibitor, can interfere with the kidney’s ability to excrete methotrexate, leading to higher systemic exposure. This makes toxicity more likely, especially with higher methotrexate doses or if kidney function is already impaired, so clinicians watch MTX levels and renal function closely or consider alternative gastric protection when needed.

Other options involve different interactions or less consistent effects in this context. NSAIDs like ibuprofen can also raise MTX levels by competing for renal clearance, but that’s a separate interaction from the one demonstrated here. Vitamin C and paracetamol don’t have the same demonstrated impact on methotrexate clearance in the material.