Editing Valproate (section)

== Interactions ==

Valproate inhibits [[CYP2C9]], [[glucuronyl transferase]], and [[epoxide hydrolase]] and is highly protein bound and hence may interact with drugs that are substrates for any of these enzymes or are highly protein bound themselves.<ref name = TGA/> It may also potentiate the CNS depressant effects of alcohol.<ref name = TGA/> It should not be given in conjunction with other antiepileptics due to the potential for reduced clearance of other antiepileptics (including [[carbamazepine]], [[lamotrigine]], [[phenytoin]] and [[Phenobarbital|phenobarbitone]]) and itself.<ref name = TGA/> It may also interact with:<ref name="Depakote FDA label" /><ref name = TGA/><ref>{{cite journal | vauthors = Herzog AG, Farina EL, Blum AS | title = Serum valproate levels with oral contraceptive use | journal = Epilepsia | volume = 46 | issue = 6 | pages = 970–971 | date = June 2005 | pmid = 15946343 | doi = 10.1111/j.1528-1167.2005.00605.x | s2cid = 7696039 | doi-access = free }}</ref>
* [[Aspirin]]: may increase valproate concentrations. May also interfere with valproate's metabolism.
* [[Benzodiazepine]]s: may cause CNS depression and there are possible pharmacokinetic interactions.
* [[Carbapenem]] antibiotics: reduce valproate levels, potentially leading to seizures.
* [[Cimetidine]]: inhibits valproate's metabolism in the liver, leading to increased valproate concentrations.
* [[Erythromycin]]: inhibits valproate's metabolism in the liver, leading to increased valproate concentrations.
* [[Ethosuximide]]: valproate may increase ethosuximide concentrations and lead to toxicity.
* [[Felbamate]]: may increase plasma concentrations of valproate.
* [[Mefloquine]]: may increase valproate metabolism combined with the direct [[epileptogenic]] effects of mefloquine.
* [[Oral contraceptive pill|Oral contraceptives]]: may reduce plasma concentrations of valproate.
* [[Primidone]]: may accelerate metabolism of valproate, leading to a decline of serum levels and potential [[breakthrough seizure]].
* [[Rifampicin]]: increases the clearance of valproate, leading to decreased valproate concentrations.
* [[Warfarin]]: valproate may increase free warfarin concentration and prolong bleeding time.
* [[Zidovudine]]: valproate may increase zidovudine serum concentration and lead to toxicity.