A retrospective study of compliance with recommended hematologic monitoring of carbamazepine

Early case reports of fatal hematologic effects associated with carbamazepine (CBZ) resulted in manufacturer recommendations for extensive laboratory monitoring. Several alternative monitoring protocols have been published, indicating disagreement with those recommendations. The manufacturer has removed specific monitoring guidelines allowing physicians to monitor CBZ during treatment based on their clinical judgment. This study was designed to determine the frequency of CBZ hematologic monitoring in one academic setting. Data on complete blood counts (CBCs) were retrospectively obtained and were compared with 1975-88 Physicians' Desk Reference recommendations for weekly CBCs during the first three months of treatment. Eighty-three patients were identified: 32 psychiatry, 37 neurology, and 14 from other clinics. Only one patient met guidelines for monitoring during the entire first three months of treatment. Comparisons between clinics demonstrated no statistically significant differences in monitoring rates. Prospective studies in academic and private practice settings are needed to provide more information on actual monitoring practices. Due to the removal of specific manufacturer recommendations, a standard approach is needed to establish consistent and adequate monitoring and to provide legal support to prescribers.