Support information on page: Treatment > 9 steps of treament > 7 - Interaction awareness

carbamazepine (Tegretol, Tegretol-XR, Carbatrol)

felbamate (Felbatol)

Felbamate is recommended for use only by patients who respond inadequately to alternative treatments and whose epilepsy is so severe that a substantial risk of aplastic anemia, liver failure, or both is deemed acceptable in light of the benefits of its use.

AEDs that increase levels	AEDs that decrease levels
valproate	carbamazepine
phenytoin	phenobarbital

gabapentin (Neurontin)

AEDs that increase levels	AEDs that decrease levels
none	none

lamotrigine (Lamictal)

AEDs that increase levels	AEDs that decrease levels
valproate	carbamazepine
phenytoin	phenobarbital

levetiracetam (Keppra)

AEDs that increase levels	AEDs that decrease levels
none	none

phenobarbital

AEDs that increase levels	AEDs that decrease levels
valproate	phenytoin (variable interaction)
phenytoin (variable interaction)

phenytoin (Dilantin, Phenytek)

AEDs that increase levels	AEDs that decrease levels
ethosuximide (variably reported)	carbazepine
felbamate
oxcarbamazepine
valproate (unbound levels)
topiramate

tiagabine (Gabitril)

AEDs that increase levels	AEDs that decrease levels
none	carbamazepine
	phenytoin
	phenobarbital

valproate (Depakote, Depakote ER, Depakene, valproic acid)

AEDs that increase levels	AEDs that decrease levels
felbamate	carbamazepine
	phenobarbital
	phenytoin

Adapted from: Schachter SC. Treatment of seizures. In: Schachter SC, Schomer DL, eds. The comprehensive evaluation and treatment of epilepsy. San Diego, CA: Academic Press; 1997. p. 61-74.
With permission from Elsevier (www.elsevier.com).
Reviewed and revised February 2004 by Barry Gidal, PharmD, University of Wisconsin-Madison.