Leucovorine (Calcium Folinate Pentahydrate)

Leucovorine is used in oncology and supportive care to address folate‑related pathways.

• High‑dose methotrexate rescue: restores normal cell replication after methotrexate‑induced toxicity.
• 5‑Fluorouracil adjunct: enhances efficacy of 5‑FU‑based regimens in colorectal cancer.
• Folate deficiency prevention: supplies reduced folate to patients with low folate stores.
• Antifolate toxicity mitigation: reduces adverse effects of drugs that inhibit dihydrofolate reductase.

• Calcium folinate provides a reduced folate cofactor that bypasses dihydrofolate reductase inhibition, allowing the synthesis of thymidylate and purine nucleotides to continue. By supplying this active folate form, it restores DNA synthesis in normal cells while antifolate agents remain active against tumor cells, thereby reducing chemotherapy‑related toxicity.

Leucovorine may cause a range of adverse reactions, most of which are mild and reversible.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Diarrhoea: loose stools that resolve with continued therapy.
• Transient liver enzyme elevation: mild increase in ALT/AST.
• Rash: mild skin erythema or itching.

Serious or Rare Side Effects

• Severe hypersensitivity: anaphylaxis or angioedema requiring immediate medical attention.
• Hematologic abnormalities: rare cases of pancytopenia.
• Renal impairment: occasional acute kidney injury.
• Pulmonary toxicity: rare interstitial pneumonitis.

Before prescribing Leucovorine, clinicians should consider patient‑specific factors and monitor for potential complications.

• Renal function: assess creatinine clearance before and during therapy.
• Hepatic function: monitor liver enzymes regularly.
• Pregnancy status: evaluate risk versus benefit if use is contemplated during pregnancy.
• Concomitant antifolates: avoid overlapping use with other folate antagonists.
• Allergies: check for known hypersensitivity to calcium folinate or excipients.
• Store at ambient temperature: keep below 25°C, in the original container, protected from moisture and direct sunlight.

Leucovorine can influence the activity of several co‑administered medicines.

Major Interactions (Avoid)

• Methotrexate high‑dose regimens: may reduce methotrexate efficacy if given simultaneously.
• Trimethoprim‑sulfamethoxazole: can increase risk of bone marrow suppression.

Moderate Interactions (Monitor Closely)

• Phenytoin: may alter folate metabolism, requiring dose adjustment.
• Anticonvulsants (e.g., carbamazepine, phenobarbital): may increase folate turnover.
• Oral contraceptives: potential reduction in folate levels, monitor for deficiency symptoms.