What is the recommended dosing regimen for 5-fluorouracil (5fu) in cancer treatment?

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Last updated: June 17, 2025View editorial policy

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From the Guidelines

The recommended dosing regimen for 5-fluorouracil (5-FU) in cancer treatment is 1000 mg/m² (continuous infusion) once per day on days 1-4 (week 1) and 29-32 (week 5), as part of a combination regimen with mitomycin-C (MMC) or cisplatin, as stated in the ASCO guideline 1.

Dosing Regimens

  • For anal cancer, the recommended dose is 1000 mg/m² (continuous infusion) once per day on days 1-4 (week 1) and 29-32 (week 5) when used in combination with MMC or cisplatin 1.
  • For colorectal cancer, common regimens include 425 mg/m² intravenously daily for 5 days every 4 weeks, or 500-600 mg/m² as a weekly infusion, with dose adjustments necessary for patients with renal or hepatic impairment 1.

Combination Therapies

  • 5-FU can be used in combination with other agents such as leucovorin, oxaliplatin, and irinotecan, with specific dosing regimens outlined in the guidelines 1.

Administration and Monitoring

  • Treatment should be administered under oncology supervision with appropriate antiemetics and hydration to manage side effects like nausea, mucositis, and myelosuppression.
  • Close monitoring for toxicities is essential, with dose adjustments made as necessary to minimize adverse effects.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION: ... The FDA drug label does not answer the question.

From the Research

Recommended Dosing Regimen for 5-Fluorouracil (5FU)

The recommended dosing regimen for 5-fluorouracil (5FU) in cancer treatment varies depending on the type of cancer, patient population, and treatment schedule.

  • For metastatic carcinoma of the pancreas, a continuous ambulatory 5FU infusion of 200-300 mg/m2/day has been used 2.
  • In a Phase I trial, the maximum tolerated dose of continuous venous infusion of 5FU was found to be 450 mg/m2/day, with mucositis being the principal dose-limiting toxic effect 3.
  • For metastatic colorectal cancer, a weekly schedule of 5FU with high-dose folinic acid modulation has been used, with a recommended dose of 720 mg/m2 per week 4.
  • In a Multicenter Phase II study, high-dose 5FU was administered as a continuous intravenous infusion at a dose of 60 mg/kg/48 hours (2400 mg/m2/48 hours) in combination with leucovorin and recombinant interferon-alpha-2b for patients with advanced colorectal cancer 5.
  • For metastatic breast cancer, a low-dose continuous intravenous infusion of 5FU at an initial daily dose of 250 mg/m2 has been used, administered continuously for 21 days followed by a 7-day rest 6.

Toxicity and Tolerance

The toxicity and tolerance of 5FU vary depending on the dosing regimen and patient population.

  • Common toxicities include mucositis, diarrhea, hand-foot syndrome, and cerebellar ataxia 2, 3, 6.
  • Hematological toxicity is generally modest, and hepatic toxicity is rare 3, 5.
  • The addition of interferon-alpha to 5FU and leucovorin increases the toxicity of 5FU-related treatments 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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