5-Fluorouracil (5-FU) Injection – Onco India International

Overview & Description

5-Fluorouracil (5-FU) Injection, manufactured by Onco India International, is a widely used chemotherapy medication. It belongs to the antimetabolite class of anticancer drugs, designed to inhibit the growth and spread of malignant cells.

It works by blocking DNA and RNA synthesis in cancer cells, primarily through inhibition of the enzyme thymidylate synthase, which is essential for DNA replication. This action prevents cancer cells from multiplying and promotes tumor shrinkage.

5-FU is administered intravenously under medical supervision, most commonly at a strength of 50 mg/mL. In oncology, it remains one of the cornerstone drugs for treating solid tumors, either as a single agent or in combination with other chemotherapeutics. It is also available in topical formulations for certain precancerous skin conditions.

Uses of 5-Fluorouracil Injection

5-FU Injection is prescribed as part of chemotherapy regimens to treat a variety of cancers by stopping cancer cell division and growth. It can be given alone or in combination with other anticancer drugs.

Common Uses:

• Colorectal Cancer: Integral in advanced or metastatic disease, often combined with leucovorin, oxaliplatin (FOLFOX), or irinotecan (FOLFIRI).

• Breast Cancer: Used in metastatic cases, usually when other therapies fail.

• Gastric (Stomach) Cancer: Effective in advanced or metastatic disease.

• Pancreatic Cancer: Administered as part of combination chemotherapy.

• Esophageal Cancer: Used to shrink tumors before surgery or as palliative treatment.

• Head and Neck Cancers: Helps reduce tumor size in the oral cavity, throat, and larynx.

• Cervical Cancer: Commonly used with radiation (chemoradiation) for locally advanced cases.

Indications

• Cancers of the gastrointestinal tract, breast, pancreas, esophagus, cervix, and head/neck region

• Used as an adjuvant both before and after surgery to shrink tumors and improve survival rates

• Standard of care in colorectal and gastric cancers

• Important in palliative care, helping control symptoms and improve quality of life

Benefits

• Proven efficacy in shrinking tumors and improving survival outcomes

• Selectively targets rapidly dividing cancer cells

• Plays a major role in the management of gastrointestinal malignancies

• Highly effective in combination chemotherapy regimens (e.g., FOLFOX, FOLFIRI)

• Provides significant benefit in palliative care of metastatic cancers

• Available in both injectable and topical formulations, expanding its clinical use

Mechanism of Action

• Converted in the body into active metabolites that inhibit thymidylate synthase, blocking DNA synthesis

• Incorporates into RNA, disrupting its function and impairing protein synthesis

• Selectively affects rapidly proliferating tumor cells while sparing most normal tissues

Directions for Use

• Administered intravenously by a healthcare professional

• Can be given as a bolus injection or a continuous infusion (hours to several days) depending on treatment protocol

• Dose and frequency are individualized based on:

  • Type of cancer

  • Patient’s body surface area (mg/m²)

  • Liver/kidney function

  • Tolerance and side effects

Dosage Guidelines

• Colorectal Cancer: 400–600 mg/m² IV bolus, or 225–600 mg/m²/day infusion

• Breast, Gastric, Pancreatic Cancers: 500–600 mg/m² IV daily (Days 1–5), repeated every 3–4 weeks

• Head & Neck Cancers (with Radiation): 600 mg/m² IV once weekly or as infusion

• Dosage adjustments may be required in patients with organ dysfunction or severe side effects

Contraindications (When Not to Use)

Avoid 5-FU Injection in patients with:

• Bone marrow suppression (low WBCs, platelets, anemia)

• Severe liver or kidney dysfunction

• Known allergy to fluoropyrimidines

• Pregnancy and breastfeeding (can cause fetal harm)

• Severe infections or immunosuppression

• DPD enzyme deficiency (↑ risk of life-threatening toxicity)

Drug Interactions

May be used with (under supervision):

• Leucovorin (enhances 5-FU activity)

• Oxaliplatin, Irinotecan (synergistic in colorectal regimens)

• Radiation therapy (chemoradiation protocols)

Avoid or use with caution:

• Blood thinners (warfarin): ↑ bleeding risk

• Phenytoin: ↑ toxicity risk

• Immunosuppressants & live vaccines: contraindicated due to immunosuppression

• Allopurinol, cimetidine: may alter 5-FU metabolism

Safety Advice (Precautions & Warnings)

• Always administered in a hospital/clinic setting under specialist supervision

• Requires frequent blood monitoring (CBC, liver and kidney function)

• Use with caution in elderly and frail patients

• Not recommended during pregnancy or breastfeeding

• Patients should avoid alcohol and live vaccines during therapy

• Report immediately if experiencing fever, infection, persistent vomiting, diarrhea, or unusual bleeding

General Instructions for Patients

• Treatment only under strict oncologist supervision

• Stay hydrated and eat a balanced diet during therapy

• Avoid pregnancy and breastfeeding during and after treatment (consult doctor for timeline)

• Do not receive live vaccines during therapy

• Attend all scheduled blood tests and check-ups to monitor side effects

Comparison with Other Chemotherapy Options

Conclusion

5-Fluorouracil Injection by Onco India International is a cornerstone chemotherapy drug with proven effectiveness in treating a wide range of cancers, especially gastrointestinal, breast, and head & neck malignancies. Its role in both curative and palliative oncology makes it indispensable in modern cancer care.