Risk factors for carbamazepine-induced leukopenia in children and adolescents

Carbamazepine (CBZ) is a commonly used anticonvulsant agent, but it has been linked with different blood cell abnormalities. This study tried to determine some of the risk factors associated with CBZ-induced leukopenia in pediatric and adolescent age group. This nested-cohort study was conducted on children and adolescents with epilepsy who received CBZ monotherapy. They included 41 patients with epilepsy. From all of the patients, baseline blood tests were obtained before starting medication and then serially. The patients were followed for at least one year. Thirteen patients (31.7%) developed leukopenia in follow-up blood tests. In one patient CBZ was discontinued after six months due to the occurrence of significant neutropenia. Four factors were associated with CBZ-induced leukopenia in these patients. The first factor was gender; leukopenia was more common among girls ( P = 0.018). The other factors were lower white blood cell counts, lower neutrophil counts and lower monocyte counts in the first complete blood count, before starting CBZ. It is very important to have a complete blood cell count in everyone before treatment with CBZ is started. Thereafter, the frequency of blood monitoring can be determined on an individual basis. It is reasonable to be very careful and follow the patient repeatedly and closely when deciding to start CBZ in a girl with borderline low white blood cells, neutrophil or monocyte count.