Treatment of severe acetaminophen poisoning with intravenous acetylcysteine.

Intravenous (IV) acetylcysteine, cysteamine, and methionine treatments were compared in patients with severe acetaminophen poisoning; a control group consisted of patients receiving supportive therapy only. Acetylcysteine proved the safest and most effective mode of treatment. Acetylcysteine was effective in preventing liver damage, hepatic failure, renal damage, and death when given eight to ten hours after poisoning. When treatment was delayed for ten to 24 hours, results were the same as in the supportive-therapy group. The alanine aminotransferase (ALT) activity remained normal in 76% of the patients treated within ten hours, as compared with 40% in both cysteamine- and methionine-treated groups and with 16% in the supportive-therapy group. The ingestion-treatment interval for complete protection with all three drugs was eight hours; beyond that time, the incidence of damage increased steadily. After 15 hours, all treatments were pointless. Based on my experience, IV administration is preferable, since nausea and vomiting may limit the effectiveness of oral therapy.