Pyrimethamine has 12 known drug interactions based on U.S. FDA drug labeling data. Of these, 1 are contraindicated combinations that should be avoided entirely. 6 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Sulfamethoxazole And Trimethoprim, Acetazolamide, Folic Acid. Patients taking Pyrimethamine should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 12
- Contraindicated
- 1
- Major
- 6
- Moderate
- 4
Contraindicated (1)
- Pyrimethamine + Sulfamethoxazole And Trimethoprim— Reports suggest megaloblastic anemia risk when pyrimethamine doses exceed 25 mg weekly with concurrent sulfamethoxazole …
Major (6)
- Pyrimethamine + Acetazolamide— Concomitant use may increase risk of bone marrow suppression and folate deficiency.
- Pyrimethamine + Folic Acid— Pyrimethamine administration results in folate deficiency.
- Pyrimethamine + Methotrexate— Concomitant use may increase risk of bone marrow suppression and folate deficiency.
- Pyrimethamine + Methotrexate Sodium— Antifolate drug that may increase methotrexate plasma concentrations, increasing risk of severe adverse reactions and po…
- Pyrimethamine + Proguanil— Concomitant use may increase risk of bone marrow suppression and folate deficiency.
- Pyrimethamine + Zidovudine— Concomitant use may increase risk of bone marrow suppression and folate deficiency.
Moderate (4)
- Pyrimethamine + Dapsone— Folic acid antagonist that may increase the likelihood of hematologic reactions when used with oral dapsone.
- Pyrimethamine + Dapsone Gel, 5%— Folic acid antagonist that may increase the likelihood of hematologic reactions when used with dapsone.
- Pyrimethamine + Lorazepam— Mild hepatotoxicity has been reported when administered concomitantly with pyrimethamine.
- Pyrimethamine + Prenatal Multivitamin Tablet And Combination Omega-3 Softgel/Mineral Capsule— High levels of folic acid may result in decreased serum levels of pyrimethamine.