Drug interactions
Hydroxyurea + Pyrimethamine
Severity: Moderate
Hydroxyurea 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
Both drugs can suppress bone marrow function. Used together they may cause additive anaemia, leukopenia and thrombocytopenia.
What this interaction means in plain words
Hydroxyurea 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.
Hydroxyurea belongs to Miscellaneous; Pyrimethamine belongs to Anti Parasitic.
Why it happens
Additive myelosuppression via folate antagonism and inhibition of ribonucleotide reductase.
What to do
Monitor complete blood counts regularly during combined use and reduce doses or interrupt therapy if cytopenias develop. Consider folinic acid with pyrimethamine.
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 Hydroxyurea
Frequently asked questions
Can I take Hydroxyurea with Pyrimethamine?
MediHelp rates the interaction as moderate. Hydroxyurea 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. Both drugs can suppress bone marrow function. Used together they may cause additive anaemia, leukopenia and thrombocytopenia.
How serious is the interaction between Hydroxyurea 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: Monitor complete blood counts regularly during combined use and reduce doses or interrupt therapy if cytopenias develop. Consider folinic acid with pyrimethamine.
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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