A 60-year-old woman with rheumatoid arthritis is prescribed ibuprofen 400 mg four times daily for joint pain. Her regular meds include ramipril, furosemide, methotrexate weekly, and folic acid weekly. What is the most clinically significant concern when supplying her ibuprofen?

• A. Risk of methotrexate toxicity
• B. Increased blood pressure due to NSAID use
• C. Gastric emptying delay causing drug interactions
• D. Reduced efficacy of ramipril

Answer: (A)

NSAIDs can markedly raise methotrexate exposure in patients taking it weekly, making methotrexate toxicity the most clinically significant concern here. Methotrexate is cleared by the kidneys, and NSAIDs lessen renal clearance by reducing prostaglandin-mediated renal perfusion and by competing for tubular transport systems that excrete MTX. This can lead to higher methotrexate levels and serious adverse effects such as bone marrow suppression, mucositis, hepatotoxicity, and nephrotoxicity, even at standard MTX doses. Although NSAIDs can affect blood pressure, gastric symptoms, or the effectiveness of ramipril, these risks are generally less acute than the potential for severe methotrexate toxicity in this patient. Given the weekly MTX regimen and folic acid supplementation, avoiding or carefully limiting NSAID use and considering alternatives like acetaminophen for pain relief is a safer course to minimize toxicity risk.