Massive carbamazepine overdose: clinical and pharmacologic observations in five episodes.
We report five episodes of carbamazepine (CBZ) intoxication in four patients. Clinically, there were four distinct stages: I--coma, seizures (CBZ levels more than 25 micrograms/ml [105 mumol/l]); II--combativeness, hallucinations, choreiform movements (15 to 25 micrograms/ml [65 to 105 mumol/l]); III--drowsiness, ataxia (11 to 15 micrograms/ml [45 to 65 mumol/l]); and IV--potentially catastrophic relapse (less than 11 micrograms/ml [45 mumol/l]). Pharmacokinetic studies revealed a prolongation of the CBZ half-life, elevation of the CBZ-epoxide/CBZ ratio, and emergence of CBZ-epoxide as a significant toxic metabolite. A treatment approach is proposed including repeated gastric lavage, detection of an insoluble tablet coagulum, electrolyte monitoring, avoidance of cathartics, and treatment of seizures with diazepam and phenytoin.
Weaver
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DF
Division of Neurology, I.W. Killam Hospital for Children, Halifax, Nova Scotia, Canada.
Camfield
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P
Fraser
A
A
D000293:Adolescent; D000328:Adult; D000374:Aggression / Q000139:chemically induced; D001259:Ataxia / Q000139:chemically induced; D002220:Carbamazepine / Q000097:blood / Q000493:pharmacokinetics / Q000506:poisoning*; D002819:Chorea / Q000139:chemically induced; D003128:Coma / Q000139:chemically induced; D005260:Female; D006212:Hallucinations / Q000139:chemically induced; D006801:Humans; D012640:Seizures / Q000139:chemically induced; D012894:Sleep Stages; D013406:Suicide, Attempted; D013997:Time Factors
D002220:Carbamazepine