Antiepileptic drugs (AEDs) polypharmacy could lead to buried pharmacokinetic interactions due to CYP450.

CYP450 enzymes are basics for the metabolism of several medications such as numerous AEDs. As AEDs polypharmacy could lead to hidden pharmacokinetic interactions due to CYP450, there fore, the aim of this study was to determine a proper guide line for AEDs prescription in Iranian epileptic population. A cross-sectional study of fifty-four patients' (n=23 females; n= 31 males with a mean age of 27 years) located in the Epilepsy Ward of Kashani Hospital of Isfahan University of Medical Sciences was carried out during the year 2011. Variables including sex, age, age of seizureonset, type and number of AEDs were recorded in d-Base. Results showed that the number of prescriptions based on AEDs polypharmacy was 77.8%. The most important drugs in prescriptions were carbamazepine (n=41) that is a potent inducer of CYP450 and valproic acid (n=31) that is a potent inhibitor of CYP450 simultaneously. Administration of AEDs was based on: three (n=17), four (n=7), five (n=4) or six (n=3) AEDs simultaneously. To avoid side effects, in prescribing AEDs that act as CYP450 inhibitors or inducers concomitantly, their spectrum of interactions should be predicted.