Valproate Interactions

Valproate increases lamotrigine concentrations more than 2-fold, requiring dose adjustment.

Source: NLP:lamotrigine

Increases lamotrigine concentrations slightly more than 2-fold. Conflicting data regarding effect on valproate concentrations.

Source: NLP:lamotrigine er

Increases plasma concentrations and reduces clearance of lorazepam. Lorazepam dosage should be reduced by approximately 50%.

Source: NLP:lorazepam

May lead to increased blood levels of propofol. Propofol dose should be reduced and patients monitored closely for increased sedation or cardiorespiratory depression.

Source: NLP:propofol

Inhibitor of epoxide hydrolase that may increase carbamazepine-10,11 epoxide levels; dosage adjustment and/or plasma level monitoring necessary.

Source: NLP:carbamazepine

CNS depressant that may potentiate CNS-depressant effects of diazepam.

Source: NLP:diazepam

Felbamate increases steady-state valproate plasma concentrations in a dose-dependent manner; valproate dosing may require reduction to avoid toxicity.

Source: NLP:felbamate

Valproate reduces intestinal folate absorption and interferes with folate-dependent metabolic pathways.

Source: NLP:folic acid

Isoniazid may increase plasma levels of valproate. Plasma valproate concentration should be monitored and dosage adjustments made as needed.

Source: NLP:isoniazid

Impairs folate absorption and increases metabolism of circulating folate.

Source: NLP:prenatal multivitamin tablet and combination omega-3 softgel/mineral capsule

Valproate increases rufinamide concentration by 16-70%; lower starting dose of rufinamide recommended (10 mg/kg/day pediatric, 400 mg/day adults).

Source: NLP:rufinamide

Tiagabine causes slight decrease (about 10%) in steady-state valproate concentrations. Valproate significantly decreases tiagabine binding in vitro, resulting in approximately 40% increase in free tiagabine concentration.

Source: NLP:tiagabine hydrochloride

Levetiracetam did not alter valproate pharmacokinetics, and valproate did not modify levetiracetam absorption, clearance, or urinary excretion.

Source: NLP:levetiracetam

Risperidone increases valproate peak plasma concentration by 20%. Dose adjustment for valproate not recommended.

Source: NLP:risperidone

When using olanzapine in combination with valproate, refer to the Drug Interactions section of valproate package insert.

Source: NLP:olanzapine