Cimetidine protects against acetaminophen toxicity.
Generally, acetaminophen (APAP) overdoses with elimination half-lives over 4 hr. sustain liver damage. In the following cases, cimetidine (C) seems to have protected against APAP toxicity. An 18 yr. old, 64 kg female smoker presented 6 hr. after taking 10Rg APAP, 1200+ mg C, and small amounts of flurazepam and Sleepeze (methaprilene + scopolamine). Three plasma APAP levels (by HPLC) revealed an elimination half-life of 4.4 hr. C did not interfere with the APAP assay. Despite the long half-life in a patient with microsomal enzymes induced by smoking, no evidence of hepatotoxicity developed. A month later, the same patient overdosed with APAP alone. Three plasma levels revealed a 3.3 hr. half-life. Lack of toxicity in the presence of a long elimination half-life may indicate a protective action of C in APAP overdoses.
D000082:Acetaminophen / Q000378:metabolism / Q000506:poisoning*; D000111:Acetylcysteine / Q000627:therapeutic use; D000293:Adolescent; D000818:Animals; D002927:Cimetidine / Q000627:therapeutic use*; D005260:Female; D006146:Guanidines / Q000627:therapeutic use*; D006801:Humans; D008099:Liver / Q000187:drug effects; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains
D006146:Guanidines; D000082:Acetaminophen; D002927:Cimetidine; D000111:Acetylcysteine