Biovorin 50 mg/5 ml contains leucovorin calcium, a medication often referred to as folinic acid. It is a form of vitamin B9 (folate) used in supportive cancer therapy and as a rescue agent to reduce the toxic effects of certain chemotherapy drugs, particularly methotrexate. Unlike regular folic acid, leucovorin does not need to be converted in the body and is immediately active, which makes it highly effective in critical clinical settings.

Mechanism of Action

Leucovorin works by bypassing the blocked folate pathway caused by drugs like methotrexate or other folate antagonists. Methotrexate inhibits an enzyme called dihydrofolate reductase, which leads to a depletion of folate in cells. This depletion affects DNA synthesis and cell replication, impacting both cancerous and healthy cells.

Leucovorin rescues normal cells by providing a direct source of tetrahydrofolate, a necessary component for DNA repair and cell survival. In cancer treatment, it is also used to enhance the effectiveness of fluorouracil (5-FU), where it stabilizes the binding of the drug to its target enzyme, improving its anti-cancer activity.

Uses

Biovorin is used in various clinical scenarios, including:

• Rescue therapy after high-dose methotrexate to protect healthy tissues

• Enhancing the effect of 5-fluorouracil (5-FU) in colorectal and other gastrointestinal cancers

• Treatment of folate deficiency-related anemias when oral folic acid is not suitable

• Antidote to folate antagonists such as trimethoprim or pyrimethamine in overdose or toxicity cases

  Adverse Effects

  Leucovorin is generally well tolerated, but some side effects may occur:

  Common Side Effects

  • Mild nausea or vomiting

  • Fatigue or general weakness

  • Allergic reactions such as rash or itching in some individuals

  Serious Side Effects (rare)

  • Allergic reactions including swelling, difficulty breathing, or severe rash

  • When used with 5-FU, it may increase toxicity, leading to:

    • Severe diarrhea

    • Mucosal inflammation or mouth ulcers

    • Bone marrow suppression, which can lower blood counts