Factors contributing to carbamazepine-macrolide interactions

Certain macrolides (e.g. clarithromycin or erythromycin) are known to interact with the carbamazepine antiepileptic drug. Carbamazepine-macrolide interaction leads to an increase in the level of carbamazepine in the blood, so inducing carbamazepine toxicity. The aim of this paper is to compare the extent of the interaction for each macrolide and to study the effects of age, gender, weight, the carbamazepine and macrolide dosages and the use of other antiepileptic drugs on the extent of the carbamazepine-macrolide interaction. Case reports published in the literature were reviewed and analysed to this end. The results show that three macrolides (erythromycin, troleandomycin and, to a lesser extent, clarithromycin) may induce carbamazepine toxicity in clinical practice. Furthermore, it was observed that high dosages of carbamazepine or macrolides and the use of concurrent anticonvulsivant drugs in the case of patients below 60 years of age are associated with the highest carbamazepine levels in carbamazepine-macrolide interactions. This study should help physicians choose a macrolide that does not interact with carbamazepine and evaluate the risk of an interaction between carbamazepine and macrolides.