Carbamazepine and its 10,11-epoxide in children and adults with epilepsy.

The plasma concentrations of carbamazepine and its 10,11-epoxide were measured in 37 children and 13 adults with epilepsy during maintenance therapy. The children formed relatively more of the epoxy metabolite than adults. The daily dose, expressed as mg/kg or mg/m2, showed a statistically significant correlation with blood level in children, but not in adults. The cerebrospinal fluid concentrations of carbamazepine and carbamazepine-10,11-epoxide in nine children were 33 and 41 per cent, respectively, of the concomitant plasma level.