Walsh & Hoyt: Antimetabolites

These drugs interfere with the production of nucleic acids by three mechanisms. Some inhibit production of the deoxyribonucleoside triphosphates that are the immediate precursors for deoxyribonucleic acid (DNA) synthesis, thus inhibiting the replication process. Extended periods of inhibition of this process are usually cytotoxic. Others are substituted for purines or pyrimidines in the anabolic nucleotide pathways. Finally, some antimetabolites produce apoptosis programmed cell death in susceptible cells. In some cases, more than one mechanism is responsible for the effects of the drug. Methotrexate (MTX). 5-Fluorouracil (5-FU). Gemcitabine. Purine analogs. Fludarabine. Cladribine. Pentostatin. Pyrimidine analogs. Bromodeoxyuridine (BUdR). Hydroxyurea.