Successful treatment of severe carbamazepine toxicity with 5 % albumin-enhanced continuous venovenous hemodialysis

Abstract

Carbamazepine overdose is a common, toxic ingestion, manifesting as central nervous system (CNS) and respiratory depression. Carbamazepine is highly protein bound with a large volume of distribution and, therefore, inefficiently removed by conventional hemodialysis. We describe the successful use of continuous venovenous hemodialysis (CVVHD) with 5% albumin enhanced dialysate in a 31-year-old female who developed CNS depression, hypotension and respiratory failure, requiring mechanical ventilation, after an intentional ingestion of approximately 10 g of extended release carbamazepine, Tegretol CR(®). The peak drug level was 26 mcg/ml, therapeutic range 8-12 mcg/ml, with toxicity often developing a level above 15 mcg/ml. Normal half-life of drug elimination is 35-60 h in carbamazepine naïve patients. In contrast, with albumin-enhanced dialysis, we observed a drug half-life of 18 h. She was extubated on day two and was transferred to inpatient psychiatry by day 3 without significant neurologic sequelae. In vitro studies have been done with bovine blood demonstrating significant carbamazepine removal using CVVHD with albumin-enhanced dialysate. There has been very limited experience using albumin-enhanced CVVHD in an adult patient with carbamazepine toxicity.