Dihydrofolate reductase inhibitor

A dihydrofolate reductase inhibitor (DHFR inhibitor) is a molecule that inhibits the function of dihydrofolate reductase, and is a type of antifolate.

Since folate is needed by rapidly dividing cells to make thymine, this effect may be used to therapeutic advantage. For example, methotrexate is used as cancer chemotherapy because it can prevent neoplastic cells from dividing. Bacteria also need DHFR to grow and multiply and hence inhibitors selective for bacterial vs. host DHFR have found application as antibacterial agents.