Hepatotoxicity following the therapeutic use of antipyretic analgesics.

The potential for hepatic injury associated with the therapeutic use of salicylates and acetaminophen has recently attracted considerable attention. About 300 cases have been reported in which elevated transaminase levels or other evidence of hepatic injury developed following treatment with salicylates. Review of the spectrum of abnormalities reveals a group of patients (4 percent) with symptomatic liver damage in whom progressive or chronic liver disease is a possibility with continued use of the drug. In a few patients in this group, jaundice developed; several had abnormal prothrombin times; 11 (70 percent) had transaminase values in excess of 500 units; and five patients (30 percent) had encephalopathy and/or Reye's syndrome. In several reports liver damage has also been associated with the use of acetaminophen in therapeutic or near-therapeutic dosages. Of 18 patients, nine appeared to have ingested acetaminophen in amounts approaching overdose. Of the remaining nine patients, six were alcoholics. In the entire group, only five patients did not have a history of alcohol abuse; in three, glutathione depletion was suggested as a possible explanation for hepatotoxicity. The association with alcoholism or glutathione depletion suggests that host susceptibility may play a critical role. In two patients, long-term use of acetaminophen resulted in liver injury suggestive of chronic active hepatitis, possibly on the basis of an idiosyncratic reaction. In a study of chronic liver disease, acetaminophen half-life was prolonged (168 percent) without accumulation at 4 g a day over five days. In a double-blind, two-week, cross-over study, no clinical or laboratory evidence of adverse effects was found. There is, therefore, no evidence that chronic liver disease increases the risk of hepatotoxicity following the administration of acetaminophen in therapeutic doses. Thus, acetaminophen is the preferred antipyretic analgesic in patients with liver disease. Salicylates should be avoided since many of the adverse effects associated with these drugs are similar to the complications of chronic liver disease.