Drug interactions
L-methylfolate + Pyrimethamine
Severity: Moderate
L-methylfolate and Pyrimethamine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
L-methylfolate is an active folate and may offset the folate-antagonist action of pyrimethamine. This could reduce antiparasitic efficacy, particularly in toxoplasmosis treatment.
What this interaction means in plain words
L-methylfolate and Pyrimethamine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
L-methylfolate belongs to Miscellaneous; Pyrimethamine belongs to Anti Parasitic.
Why it happens
Pharmacodynamic antagonism, since supplied reduced folate bypasses the dihydrofolate reductase blockade.
What to do
Avoid routine L-methylfolate supplementation while treating infection with pyrimethamine unless a clear indication exists. Use folinic acid for marrow protection and monitor clinical response and blood counts.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Pyrimethamine
- Deferiprone + Pyrimethamine Major
- Eliglustat + Pyrimethamine Major
- Acalabrutinib + Pyrimethamine Moderate
- Brexpiprazole + Pyrimethamine Moderate
- Dapsone + Pyrimethamine Moderate
- Folic acid + Pyrimethamine Moderate
Other interactions of L-methylfolate
Frequently asked questions
Can I take L-methylfolate with Pyrimethamine?
MediHelp rates the interaction as moderate. L-methylfolate and Pyrimethamine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. L-methylfolate is an active folate and may offset the folate-antagonist action of pyrimethamine. This could reduce antiparasitic efficacy, particularly in toxoplasmosis treatment.
How serious is the interaction between L-methylfolate and Pyrimethamine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid routine L-methylfolate supplementation while treating infection with pyrimethamine unless a clear indication exists. Use folinic acid for marrow protection and monitor clinical response and blood counts.
What other medicines interact with Pyrimethamine?
MediHelp also lists interactions of Pyrimethamine with, for example, Deferiprone, Eliglustat, Acalabrutinib. The full list is on the Pyrimethamine page.
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