antifolater

Antifolater is a rarely used term with no widely accepted definition in standard reference works. In practice, the word may refer to (a) an agent or person acting to antagonize folate metabolism (an antifolate), or (b) a casual or erroneous label for someone who opposes folate supplementation or fortification. Because usage varies, the term should be interpreted in its specific context and sources consulted.

In pharmacology, antifolates are drugs that inhibit folate-dependent enzymatic steps required for DNA synthesis. They disrupt synthesis of thymidylate and purines, primarily by targeting enzymes such as dihydrofolate reductase (DHFR) or enzymes in the folate cycle. These drugs are used as anticancer agents and antimicrobials and are typically described as antifolates rather than antifolaters.

Common antifolate drugs include methotrexate, pemetrexed, and raltitrexed (DHFR inhibitors and other targets); trimethoprim and pyrimethamine (DHFR inhibitors); and sulfonamide antibiotics that inhibit dihydropteroate synthase in bacteria. The antimetabolite action preferentially affects rapidly dividing cells, though toxicity to normal tissues limits use.

In discussions of public health and nutrition, antifolater might describe a person who questions or opposes folic acid fortification or supplementation policies. Proponents cite benefits of reducing neural tube defects, while opponents warn of uncertain long-term effects or concerns about masking vitamin B12 deficiency.

See also: antifolate, dihydrofolate reductase inhibitors, neural tube defect prevention, folic acid fortification.