1 May 2026Oral drugs
Calcium folinate = Folinic acid oral
Folinic acid guidance for preventing pyrimethamine-related hematologic toxicity during toxoplasmosis and isosporiasis care.
Prescription under medical supervision
This guide page is for structured reference only and does not replace a clinician, pharmacist, or emergency review. Dose choice, route choice, interactions, and safety decisions still need professional judgment.
Therapeutic action
Antidote to folate antagonists.
Indications
Prevention of haematological toxicity of pyrimethamine when pyrimethamine is used as prophylaxis for, or in the treatment of, toxoplasmosis or isosporiasis in immunodeficient patients.
Forms and strengths
- 15 mg tablet.
- Also comes in 5 mg and 25 mg capsules.
Dose
When pyrimethamine is used as primary or secondary prophylaxis for toxoplasmosis
- Adult: 25 to 30 mg once weekly.
During treatment of toxoplasmosis
- Adult: 10 to 25 mg once daily.
During treatment of isosporiasis
- Adult: 5 to 15 mg once daily.
Duration
For the duration of the pyrimethamine treatment.
Contra-indications, adverse effects, precautions
- Pregnancy: no contra-indication.
- Breast-feeding: no contra-indication.
- Folic acid cannot be used as an alternative to folinic acid for the treatment of toxoplasmosis because folic acid reduces the antiprotozoal activity of pyrimethamine.
Source
MSF Essential drugs practical guidelines (January 2026)
This page reproduces the structured reference information for this batch while leaving out the Storage and Remarks sections.
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