[Carbamazepine "CR"--clinical picture of intoxication: the kinetics of extracorporeal elimination].

Abstract

Carbamazepine (CBZ) intoxication is an important issue in acute poisonings practice. Pathological reflexes, central breathing depression and cardiac disturbances are the characteristic features of carbamazepine poisoning. The clinical picture is variable and does not always correlate with CBZ serum concentration. Controlled-release formulations of CBZ have a delay of over 48h between the time of ingestion and peak serum CBZ concentrations. Peristalsis paralysis makes the extracorporeal elimination a treatment of choice in this case. Unfortunately, the effectiveness of this procedure is not clearly established -the results are often contradictory which makes it difficult to set standards for elimination treatment. In this research we report 2 cases of controlled-release CBZ poisonings. Deterioration in the clinical state characterized mainly by central breathing depression appeared after 51 hrs (patient I) and 74 hrs (patient II) from CBZ ingestion. Charcoal hemoperfusion (HP) improved patients clinical state. During the HP procedure the mean CBZ plasma half-life (T(1/2)) was 6.67 h and 12.66 h. Those values were a few times lower then those measured after the cessation of HP. The mean charcoal column clearances (with blood flow 180 ml/min) were 77.2 and 108.9 ml/min. CBZ pharmacokinetics makes the drug move rapidly between the compartments during the HP. This movement may cause a reduction in CBZ concentrations in receptors' vicinity. Probably this mechanism accounts for the improvement of the patients' clinical state despite low kinetic values of the procedure.