Leucovorin

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Leucovorin

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Generic Name
leucovorin

Leucovorin comes in intravenous (IV), intramuscular (IM) injection (shot), and oral form.

How It Works

Leucovorin is a derivative of folic acid. Leucovorin works differently depending on whether it is used with methotrexate (MTX) or fluorouracil (5-FU).

  • Methotrexate: Leucovorin is given to "rescue" the gastrointestinal lining and bone marrow cells from MTX toxicity. Most of the complications and side effects of methotrexate can be either prevented or treated by using leucovorin, which is usually given 24 hours after methotrexate.
  • Fluorouracil: Leucovorin increases the effectiveness of 5-FU, increasing the anti-cancer effect.

Why It Is Used

Leucovorin is used with either methotrexate (MTX) for the treatment of ectopic pregnancy or fluorouracil (5-FU) for cancer treatment.

How Well It Works

Most of the complications and side effects of methotrexate can be either prevented or treated by using leucovorin, which is usually given 24 hours after the methotrexate is given.

Leucovorin enhances the binding of fluorouracil (5-FU) and prolongs the lifespan of 5-FU, increasing the anti-cancer effect.1

Side Effects

Leucovorin is very well tolerated and has almost no side effects of its own.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Leucovorin generally decreases the severity of side effects of MTX. It can increase the severity of the side effects of 5-FU when used with that medicine.

Leucovorin should be administered only under the supervision of a medical oncologist.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.

References

Citations

  1. Meyerhardt JA, Mayer RJ (2005). Systemic therapy for colorectal cancer. New England Journal of Medicine, 352(5): 476–486.

Credits

By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Andrew Swan, MD, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer Arvydas D. Vanagunas, MD - Gastroenterology
Last Revised December 30, 2010

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