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

Abstract

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 was 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 (Student's 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.