Table 2.

Clinically Important Interactions Between AEDs and with other Drug Classes

Affected Drug Classes
AEDs Susceptible to Interactions	AEDs	Antidepressants and Antipsychotics	Oral Contraceptives	Antimicrobal Drugs	Various (e.g. Warfarin, Antineoplastic Drugs, Immuno-Suppressants)
Enzyme inducers that will decrease serum concentrations of affected drugs
Carbamazepine, phenobarbital, phenytoin, primidone	Benzodiazepines, ethosuximide, lamotrigine, oxcarbazepine, pregabalin, rufinamide, stiripentol, tiagabine, topiramate, zonisamide, valproic acid,	Typical: Chlorpromazine, haloperidol Atypical: Aripiprazol, clozapine, olanzapine, quetiapine, risperidone, ziprasidone Antidepressants: Clomipramine Imipramine	Estrogen component of combination pills	Doxycycline, indinavir, itraconazole, metronidazol, praziquantel	Warfarin Antineoplastic agents (e.g. cyclophosphamide, irinotecan, methotrexate, tamoxifen) Immuno-suppressants: Ciclosporin, tacrolimus Varia: Cortisol derivatives, dextropropoxyphene, dihydropyridine calcium antagonists, fentanyl, statines, methadone, theophylline, thyroxine
Eslicarbazepine and oxcarbazepine	Lamotrigine, phenobarbital, phenytoin, (mainly induction)		Estrogen component of combination pills
Felbamate	Carbamazepine Clobazam
Topiramate	Phenytoin (in some cases)		Estrogen component of combination pills (topiramate doses >200 mg/day)		Carboanhydrase inhibitors, digoxin, hydrochlortiazide, metformin, pioglitazone,
Enzyme inhibitors that will increase serum concentrations of affected drugs
Valproic acid	Carbamazepine, ethosuximide, lamotrigine, phenobarbital, rufinamide	Amitriptyline, nortriptyline		Carbapenem antibiotics: Imipenem, meropenem, panipenem	Cisplatin,etoposide
Felbamate	Clonazepam phenobarbital, phenytoin, valproic acid		Estrogen component of combination pills		Warfarin
Rufinamide	Carbamazepine, clobazam, phenytoin, phenobarbital, valproic acid		Estrogen component of combination pills		Triazolam
Stiripentol	Carbamazepine, clobazam, phenytoin, phenobarbital, valproic acid				Various potential interactions*

AEDs=Antiepileptic drugs. The list is not all-including but relevant examples are given. Several references are used, see text for details and selected reviews, [7-13] and the spc of the various drugs. Oral contraceptives and warfarin are described in more detail in Table 4. ^* In vitro studies suggest a potential for interactions with most drug classes metabolized by CYP3A4, 1A2, 2C19.

^* In vitro studies suggest a potential for interactions with most drug classes metabolized by CYP3A4, 1A2, 2C19.