Valproate has 20 known drug interactions based on U.S. FDA drug labeling data. 9 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Carbamazepine, Felbamate, Lamotrigine. Patients taking Valproate 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
- 20
- Major
- 9
- Moderate
- 7
- Minor
- 3
Major (9)
- Valproate + Carbamazepine— CYP3A4 and epoxide hydrolase inhibitor; increases carbamazepine-10,11-epoxide plasma concentrations. Dosage adjustment a…
- Valproate + Felbamate— Felbamate increases steady-state valproate plasma concentrations in a dose-dependent manner, requiring monitoring and po…
- Valproate + Lamotrigine— Valproate increases lamotrigine concentrations more than 2-fold, requiring dose adjustment.
- Valproate + Lamotrigine Extended-Release— Increases lamotrigine concentrations slightly more than 2-fold. Conflicting data regarding effect on valproate concentra…
- Valproate + Lorazepam— Increases plasma concentrations and reduces clearance of lorazepam. Lorazepam dosage should be reduced by approximately …
- Valproate + Phenytoin— Concomitant administration has been associated with increased risk of valproate-associated hyperammonemia. Patients shou…
- Valproate + Pivmecillinam— Concurrent use may decrease carnitine concentrations and increase risk of carnitine depletion-associated adverse reactio…
- Valproate + Propofol— May lead to increased blood levels of propofol. Propofol dose should be reduced and patients monitored closely for incre…
- Valproate + Propofol Injectable Emulsion— Concomitant use may lead to increased blood levels of propofol. Propofol dose should be reduced and patients monitored c…
Moderate (7)
- Valproate + Diazepam— CNS depressant that may potentiate CNS-depressant effects of diazepam.
- Valproate + Folic Acid— Valproate reduces intestinal folate absorption and interferes with folate-dependent metabolic pathways.
- Valproate + Isoniazid— Isoniazid may increase plasma levels of valproate. Plasma valproate concentration should be monitored and dosage adjustm…
- Valproate + Lamotrigine Chewable Dispersible— Increased lamotrigine concentrations slightly more than 2-fold. Conflicting data on effect of lamotrigine on valproate c…
- Valproate + Prenatal Multivitamin Tablet And Combination Omega-3 Softgel/Mineral Capsule— Impairs folate absorption and increases metabolism of circulating folate.
- Valproate + Rufinamide— Valproate increases rufinamide concentration by 16-70%; lower starting dose of rufinamide recommended (10 mg/kg/day pedi…
- Valproate + Tiagabine Hydrochloride— Tiagabine causes slight decrease (about 10%) in steady-state valproate concentrations. Valproate significantly decreases…
Minor (3)
- Valproate + Levetiracetam— Levetiracetam did not alter valproate pharmacokinetics, and valproate did not modify levetiracetam absorption, clearance…
- Valproate + Risperidone— Risperidone increases valproate peak plasma concentration by 20%. Dose adjustment for valproate not recommended.
- Valproate + Zonisamide— Non-enzyme inducing AED; zonisamide half-life of 46 hours when used concomitantly. No appreciable effect on steady-state…