Charcoal hemoperfusion in the treatment of two cases of acute carbamazepine poisoning.

Charcoal hemoperfusion is effective in the treatment of acute carbamazepine (CBZ) poisoning, its efficacy depending on the metabolic capacity of the patient involved. This was assessed in two cases of CBZ poisoning in which CBZ and its metabolite carbamazepine-10,11-epoxide (CBZO) were monitored. One patient had not been treated with CBZ or other enzyme-inducing drugs before the overdose ingestion. The CBZO/CBZ plasma concentration ratio of this patient was 0.15 +/- 0.01 (mean +/- s.d.), indicating a normal metabolic capacity. The average clearance values obtained with the Haemocol were 85 ml/min for CBZ and 81 ml/min for CBZO. The other patient had been on long-term treatment with anticonvulsive drugs before. The CBZO/CBZ ratio was 1.58 +/- 0.16, indicating a high metabolic capacity and, consequently, a high intrinsic clearance. The average clearances obtained with the Adsorba 300 C were 129 ml/min for CBZ and 133 ml/min for CBZO. Saturation of a charcoal column can occur during a four hours treatment, in particular if the plasma CBZO concentration is high. CBZ and CBZO were also monitored in erythrocytes. The erythrocyte/plasma concentration ratios of CBZ were 0.90 +/- 0.11 (mean +/- s.d.) and 1.36 +/- 0.10. CBZO was 30-40 per cent more concentrated in erythrocytes than was CBZ. The erythrocyte/plasma concentration ratios of CBZO were 1.36 +/- 0.10 and 1.80 +/- 0.23.