Pemetrexed safety and dosing strategy.

Pemetrexed is a novel antifolate/antimetabolite that inhibits several folate-dependent enzymes, including thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide transformylase. As a class, antifolates have been associated with sporadic severe myelosuppression with gastrointestinal toxicity. Although infrequent, a combination of such toxicities carries a high risk of potentially life-threatening complications. Severe …