Treating carbamazepine poisoning: supportive or aggressive?

E.M. Atsma, C.E. Douma, I Mulder, M. Pereboom, J. Weenink

Woensdag 20 april 2016

15:00 - 15:10u in Auditorium 1

Categorie├źn: Parallelsessie

Parallel sessie: Parallelsessie 1: Case reports/research

Introduction: Carbamazepine poisoning may be complicated by serious neurologic, cardiovascular and anticholinergic symptoms. After a large single overdose its elimination half-life averages 35 hours with significant enterohepatic circulation. Serum concentrations may not peak within 96 hours. Therapy is mainly supportive since beneficial effects of gastrointestinal decontamination and hemodialysis are still a matter of debate. We felt forced to combine both strategies in a case of severe carbamazepine poisoning and studied their contribution on elimination.

Case: A 24-year-old female presented 1.5 hours after ingestion of 24000 mg immediate-release carbamazepine (serum level 24 mg/L (toxicity > 12 mg/L)). Activated charcoal was administered after gastric lavage, but had to be discontinued when vomiting and CNS depression occurred. Intubation followed and high-flux hemodialysis was started shortly after admission. However, after 4 sessions (57 hours postingestion) serum carbamazepine peaked to 45mg/L. We calculated by use of carbamazepine dialysate concentrations from a 6 hour-long session that only 3% of the ingested amount was eliminated every session. Therefore hemodialysis was stopped and we stimulated enteral elimination by combining macrogol, neostigmine and charcoal. After stools were passed, serum levels decreased rapidly. Complete clinical recovery was observed within 24 hours after gastrointestinal decontamination was initiated.

Discussion: Although we observed that serum levels decreased during dialysis this case illustrates the ineffectiveness of hemodialysis to eliminate significant amounts of carbamazepine. Enteral resorption may continue during days, even after ingestion of immediate-release tablets. In case of life-threatening poisoning an aggressive attempt for gastrointestinal decontamination seems justified after securing the airway.