Role of P-glycoprotein inhibitors in children with drug-resistant epilepsy.

The role of P-glycoprotein (Pgp), one of the known multidrug transporters, has been suggested in drug-resistant epilepsy (DRE). The following study aimed to measure the serum level of Pgp as a possible indicator of tissue Pgp overexpression in patients with DRE and to assess the efficacy of verapamil (as a Pgp inhibitor agent) in these patients. A group of 24 patients with DRE were recruited and subdivided into two groups, one receiving verapamil and the other receiving a placebo in a double-blind randomized study. Pgp serum levels were measured at enrollment and 12 months later. Twenty medically controlled epileptic patients served as a control group. A significant statistical increase was found in the Pgp level of patients when compared the control group. Patients on both verapamil and the placebo showed improvement in seizure frequency and severity where statistical analysis showed no significant differences. Pgp serum levels in patients with DRE were significantly elevated compared to patients with medically controlled epilepsy. The effect of verapamil as Pgp inhibitor on DRE requires further evaluation and research.