Use of erythromycin to inhibit carbamazepine metabolism in children with partial complex seizures

The administration of erythromycin was previously reported to increase the blood level of carbamazepine (CBZ), resulting in unexpected and severe intoxication in children with epilepsy [1-3]. The mechanism of this interaction is presumed to be inhibition of the P450 enzyme system, producing decreased CBZ clearance when the two medications are given together [4]. We have used this effect to achieve therapeutic levels of CBZ in young children affected by symptomatic drug-resistant partial seizures, in whom we were unable to obtain adequate levels despite a dose increase because of individual metabolism.