Fosphenytoin has 8 known drug interactions based on U.S. FDA drug labeling data. 2 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Carboplatin, Imatinib, Carbamazepine. Patients taking Fosphenytoin 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
- 8
- Major
- 2
- Moderate
- 6
Major (2)
- Fosphenytoin + Carboplatin— Carboplatin decreases fosphenytoin serum levels, which may lead to exacerbation of seizures.
- Fosphenytoin + Imatinib— Enzyme-inducing anti-epileptic drug that decreases imatinib AUC by 73%, significantly reducing imatinib exposure.
Moderate (6)
- Fosphenytoin + Carbamazepine— CYP3A4 inducer that decreases carbamazepine plasma levels. Carbamazepine levels and/or dosage adjustment may be necessar…
- Fosphenytoin + Doconexent, Niacinamide, .Alpha.-Tocopherol Acetate, Dl-, Cholecalciferol, .Beta.-Carotene, Ascorbic Acid, Thiamine Mononitrate, Riboflavin, Pyridoxine Hydrochloride, Cyanocobalamin, Iron, Zinc Oxide, Cupric Oxide, Potassium Iodide, Magnesium Oxide, Folic Acid, And Levomefolate Calcium— High doses of folic acid may decrease serum levels of this anticonvulsant drug.
- Fosphenytoin + Ifosfamide— CYP3A4 inducer may increase metabolism of ifosfamide to active metabolites and increase formation of neurotoxic/nephroto…
- Fosphenytoin + Prenatal Multivitamin Tablet And Combination Omega-3 Softgel/Mineral Capsule— Impairs folate absorption and increases metabolism of circulating folate.
- Fosphenytoin + Prenatal Supplement With Dha— High doses of folic acid may result in decreased serum levels of fosphenytoin.
- Fosphenytoin + Tinidazole— Concomitant administration may affect fosphenytoin pharmacokinetics. Adjustment of anticonvulsant and/or tinidazole dose…