Induction of CYP1A2 activity by carbamazepine in children using the caffeine breath test

Aims Carbamazepine is a known enzyme inducer. The aim of this study was to determine whether carbamazepine induces the metabolism of caffeine in children. Methods Children due to receive carbamazepine for epilepsy were recruited into the study. The caffeine breath test uas carried out prior to the administration of carbamazepine and after a minimum of 2-3 weeks therapy. Five children were studied and they received 200-600 mg carbamazepine daily. Results The mean values of the 2 h cumulative labelled carbon dioxide were 3.47% before and 7.65% during carbamazepine. There was a significant increase in the percentage labelled caffeine exhaled as carbon dioxide during the administration of carbamazepine (Students paired t-test, P<0.05). Conclusions The results suggest that carbamazepine induces the metabolism of caffeine by the CYP1A2 pathway in the children studied.