What it does
Fluorouracil is a medication used primarily in cancer treatment. It helps to slow down or stop the growth of cancer cells.
Commonly used for: cancer of the skin, breast cancer, colon cancer, stomach cancer
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Source: Pharmacy and Poisons Board · fetched 2026-01-28 21:17:30 · updated 2026-07-20 09:00:43
About this medicine
Fluorouracil is a medication used primarily in cancer treatment. It helps to slow down or stop the growth of cancer cells.
What it treats
- cancer of the skin
- breast cancer
- colon cancer
- stomach cancer
How it works
Fluorouracil works by interfering with the growth and reproduction of cancer cells, making it harder for them to multiply.
Who it's for
Fluorouracil is prescribed for adults diagnosed with certain types of cancer.
Cautions
- • May cause side effects like nausea and hair loss.
- • Patients should inform their doctor of any other health conditions.
- • Regular blood tests may be needed to monitor health.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
Clinical monograph: flourouracil
Fluorouracil is an antimetabolite and an antineoplastic (anticancer) agent that is primarily used in the treatment of various cancers, including colorectal cancer, breast cancer, and skin cancers such as basal cell carcinoma and squamous cell carcinoma. It functions by interfering with the synthesis of DNA and RNA, inhibiting cell proliferation and leading to cell death, particularly in rapidly dividing cancer cells.
Indications
- Colorectal cancer
- Breast cancer
- Basal cell carcinoma
- Squamous cell carcinoma
- Gastric cancer
- Pancreatic cancer
Dosage
Children: Refer to the BNF for Children for appropriate dosing information in pediatric patients, as this may vary based on the specific indication and child’s health status.
Adults: Refer to the specific clinical guidelines or BNF for exact dosing information, as it varies based on cancer type and treatment regimen.
Mechanism of action
Fluorouracil is a pyrimidine analog that gets converted into active metabolites which inhibit thymidylate synthase. This enzyme is critical for the de novo synthesis of thymidine, a nucleotide necessary for DNA replication. By inhibiting thymidylate synthase, fluorouracil effectively reduces the availability of thymidine, leading to impaired DNA synthesis and cell division, particularly in cancer cells.
Pharmacodynamics
Fluorouracil exhibits a dose-dependent cytotoxic effect on cancer cells. Its mechanism of action leads to disruption of the balance between nucleotide pools necessary for DNA synthesis, resulting in cell cycle arrest and apoptosis in susceptible tumor cells. The drug has a greater effect on cells that are in the S-phase of the cell cycle, where DNA synthesis occurs.
Pharmacokinetics
Fluorouracil is administered intravenously or topically and is rapidly absorbed and distributed throughout the body. It is metabolized primarily in the liver by the enzyme dihydropyrimidine dehydrogenase (DPD) into inactive metabolites. The elimination half-life varies depending on the route of administration and the presence of DPD activity. Renal excretion is the primary route of elimination for its metabolites. Dose adjustments may be necessary in patients with impaired liver function.
Contra-indications
- Hypersensitivity to fluorouracil or any of its components
- Severe bone marrow depression
- Concomitant use with certain other antimetabolites
Adverse effects
- Nausea
- Vomiting
- Diarrhea
- Mucositis
- Bone marrow suppression
- Hand-foot syndrome
- Skin reactions
- Alopecia
Interactions
- Increased toxicity if used with other antimetabolites
- Potential interactions with anticoagulants
- May enhance the effects of certain drugs metabolized by the liver
Precautions
- Use with caution in patients with hepatic impairment
- Monitor blood counts regularly during therapy
- Avoid exposure to sunlight due to potential photosensitivity
Pregnancy
Fluorouracil is classified as Category D. It may cause fetal harm and is contraindicated in pregnancy unless the potential benefit justifies the risk.
Breast-feeding
It is not known whether fluorouracil is excreted in human milk. Caution is advised when administering to nursing mothers.
Storage
Store at room temperature, away from light and moisture. Protect from freezing.
Formulations
- Injection for intravenous use
- Topical cream for local treatment
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.