Regarding Methotrexate administration, which statement is incorrect?

• A. Kidney failure
• B. Weekly administration
• C. Side effect: Bone marrow depression
• D. Side effect: Liver fibrosis

Answer: (A)

The key idea is how methotrexate is used and what its usual toxicities are. Methotrexate is given weekly rather than daily to limit cumulative toxicity, and its well-known adverse effects include bone marrow suppression and liver toxicity (which can progress to liver fibrosis with long-term use). While the drug is cleared by the kidneys and high doses can cause nephrotoxicity if hydration is inadequate or renal function is poor, kidney failure is not a typical, predictable adverse effect of standard methotrexate therapy. In other words, kidney failure is not the expected adverse effect you would rely on as a common risk, whereas weekly dosing and the hematologic and hepatic toxicities are characteristic.