Acetylcysteine for treatment of acetaminophen toxicosis in the cat
St Omer, V.V.; McKnight, E.D.
Journal of the American Veterinary Medical Association 176(9): 911-913
1980
ISSN/ISBN: 0003-1488 PMID: 7400022 Document Number: 154577
Acute intoxication with the analgesic acetaminophen was associated with cyanosis, hyperventilation, depression, and facial oedema. Abnormal laboratory findings were methaemoglobinaemia and elevated serum alanine aminotransferase activity. In one trial, each of ten cats was given a 325-mg tablet of acetaminophen, then another after 4 hours. Five of the cats were given antidotal treatment with acetylcysteine (140 mg/kg orally) at the time of the second dosing with acetaminophen and at 8-hour intervals thereafter for a total of three treatments. All treated cats survived. Two of the untreated cats died. In another trial, doubling each dose of acetaminophen (650 mg) proved fatal in all of four untreated cats. When antidotal therapy was initiated at the time of the second dosing with acetaminophen and repeated 8- or 4-hour intervals for three treatments, two of four cats in each treatment group survived. Although antidotal therapy was associated with a return of serum glutamic-pyruvic transaminase and methaemoglobinaemia values toward normal, only the methaemoglobin value was a reliable prognostic indicator.