Fluorouracil API (5-FU)

Fluorouracil (5-FU) is an antineoplastic agent used in the treatment of various cancers. As an Active Pharmaceutical Ingredient (API), its main role is to disrupt cancer cell growth. Here's a more detailed overview:

Mechanism of Action:

1. Inhibition of Thymidylate Synthase: Fluorouracil is a pyrimidine analog that gets converted inside cells to fluorodeoxyuridine monophosphate (FdUMP). FdUMP binds to thymidylate synthase, a critical enzyme involved in DNA synthesis, forming a stable complex. This binding inhibits the enzyme's activity, leading to decreased production of thymidine, an essential nucleotide for DNA replication and repair.
2. Disruption of DNA and RNA Synthesis: By inhibiting thymidylate synthase, fluorouracil interferes with DNA synthesis and repair, ultimately leading to cell cycle arrest and apoptosis (programmed cell death). Additionally, fluorouracil can also affect RNA synthesis and function.

Indications:

• Colorectal Cancer: Often used in combination with other drugs such as leucovorin or oxaliplatin.
• Breast Cancer: Frequently used in combination with other chemotherapy agents.
• Stomach Cancer: Used either alone or in combination with other drugs.
• Skin Cancer: Applied topically for superficial basal cell carcinoma and actinic keratosis.

Administration:

• Intravenous (IV) Injection: For systemic treatment of cancer.
• Topical Application: For skin cancers and precancerous lesions.

Dosage Forms:

• Injectable Form: Solutions for intravenous infusion.
• Topical Cream/Ointment: For localized skin treatments.

Side Effects:

• Common: Nausea, vomiting, diarrhea, mucositis (inflammation of mucous membranes), and myelosuppression (decreased blood cell production).
• Serious: Cardiotoxicity (heart-related issues), severe infections, and neurological effects.

Drug Interactions:

• Leucovorin: Often used in combination to enhance the efficacy of fluorouracil.
• Other Chemotherapy Drugs: Can have additive toxic effects when combined with other cytotoxic agents.

Fluorouracil's efficacy and side effects can vary depending on the specific cancer type, the patient's overall health, and concurrent treatments. Its use and dosage are carefully managed to balance effectiveness with potential risks.