How it works
Fluorouracil is an antimetabolite that is converted into several active metabolites after administration. One major mechanism involves FdUMP, which inhibits thymidylate synthase, an enzyme required for DNA synthesis. Other active metabolites may become incorporated into RNA and DNA, disrupting normal nucleic-acid synthesis. As a result, rapidly dividing cells may lose their ability to grow and reproduce normally, ultimately leading to cell death.
Who may be prescribed this medicine
The specific treatment regimen is determined by the oncologist according to tumor type and stage, the patient's overall condition, and the other medicines included in the treatment protocol.
Research and clinical evidence
Fluorouracil is a long-established cytotoxic medicine that has been studied extensively and has been used in oncology since the 1960s. Current prescribing information supports its use for adenocarcinoma of the colon and rectum, breast, stomach, and pancreas. In clinical oncology, fluorouracil is frequently administered as part of combination chemotherapy rather than as a standalone treatment.
Pharmacological studies have demonstrated that fluorouracil primarily interferes with processes required by rapidly dividing cells. This mechanism contributes to its antitumor activity but also explains its effects on some healthy tissues with a high rate of cellular turnover.
An important aspect of modern fluorouracil treatment is assessment of dihydropyrimidine dehydrogenase (DPD) deficiency. Certain DPYD genetic variants associated with complete DPD deficiency can substantially increase the risk of severe or fatal fluorouracil toxicity. Current U.S. prescribing information recommends DPYD genetic testing before treatment when immediate therapy is not required.
Fluorouracil is used to treat certain malignant tumors, particularly adenocarcinoma of the colon and rectum, breast, stomach, and pancreas. Depending on the cancer diagnosis, it may be used in specific regimens or, more commonly, as one component of combination chemotherapy.
The primary purpose of treatment is to inhibit tumor-cell growth and proliferation. Fluorouracil disrupts DNA and RNA synthesis and therefore has a pronounced effect on cells that are actively progressing through the cell cycle.
The medicine is administered intravenously either as an intravenous bolus or as an intravenous infusion. The dose, treatment duration, and intervals between administrations are individualized according to the cancer diagnosis, chemotherapy regimen, patient condition, and treatment tolerance. Fluorouracil must be prepared and administered by qualified healthcare professionals experienced in handling cytotoxic antineoplastic medicines.
Side effects
Fluorouracil may cause serious adverse reactions and therefore requires appropriate clinical and laboratory monitoring throughout treatment.
