Phenytoin/Oxcarbazepine
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Medical warning:
Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
Oxcarbazepine may slow down how quickly your liver processes phenytoin. Phenytoin may speed up how quickly your liver processes oxcarbazepine.
What might happen:
The amount of phenytoin in your blood may increase and cause more side effects. The amount of oxcarbazepine in your blood may decrease and it may not work as well.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Let your doctor know if you have any nausea, vomiting, confusion, dizziness, or if have more seizures than normal.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
References:
1.Trileptal (oxcarbazepine) US prescribing information. Novartis Pharmaceuticals Corporation March, 2011.
2.Lakehal F, Wurden CJ, Kalhorn TF, Levy RH. Carbamazepine and oxcarbazepine decrease phenytoin metabolism through inhibition of CYP2C19. Epilepsy Res 2002 Dec;52(2):79-83.
3.McKee PJ, Blacklaw J, Forrest G, Gillham RA, Walker SM, Connelly D, Brodie MJ. A double-blind, placebo-controlled interaction study between oxcarbazepine and carbamazepine, sodium valproate and phenytoin in epileptic patients. Br J Clin Pharmacol 1994 Jan;37(1):27-32.
