Are 5–7 Days of Folic Acid Supplementation Necessary prior to Pemetrexed? Observations from a Case Series

OBJECTIVE: Current regulatory guidelines advise 5–7 days of folic acid supplementation prior to pemetrexed. Although taking folic acid during and after pemetrexed therapy is important, it remains unclear whether premedication is truly necessary, particularly as it can be inconvenient for patients, can contribute to their anxiety by delaying chemotherapy, and can create challenges in scheduling chemotherapy. METHODS AND RESULTS: We retrospectively sought to identify and evaluate outcomes among non-small cell lung cancer patients who received less than the advised folic acid premedication. Only 8 patients were identified. However, upon critical examination of first-cycle chemotherapy outcomes, we observed no major adverse events with a shortened course of folic acid premedication. CONCLUSION: In the very rare circumstance where urgent therapy is warranted, a healthcare provider can lookto this small case series and find modest precedent for the safe administration of pemetrexed in the absence of a full week of folic acid premedication.