Which statement about methotrexate and folic acid scheduling is correct?

• A. Folic acid weekly on a day different from methotrexate dosing
• B. Folic acid daily
• C. Not needed
• D. Folic acid only if side effects occur

Answer: (A)

The key idea is balancing safety with efficacy by timing folic acid so it protects normal cells without blunting methotrexate’s effect. Giving folic acid on a day that is different from the methotrexate dose allows the drug to work when it’s administered, while still providing folate support to reduce toxicity on the non-methotrexate days. This is why weekly folic acid on a non-MTX day is the best approach: it lowers mucosal and hepatic toxicity and cytopenias without significantly decreasing methotrexate’s therapeutic action.

Daily folic acid could lessen MTX’s efficacy by replenishing folate too broadly across all doses. Not needed ignores a common strategy to reduce adverse effects, and taking folic acid only if side effects occur fails to prevent toxicity.