Acute renal dysfunction in acetaminophen poisoning

Although acetaminophen (APAP)-associated liver injury is well recognized, there are few reports describing APAP nephrotoxicity, and most of them are single cases. It has also been suggested that N-acetylcysteine (NAC), used to treat the hepatotoxicity, may be harmful to the kidneys. To examine this contention and to determine whether renal involvement in APAP poisoning is at all common, we analyzed the incidence and outcome of acute renal dysfunction in patients hospitalized for APAP overdose reported to our regional poison center over a year. Eleven APAP-poisoned patients had elevated liver function tests; nine of them had azotemia. Those with higher AST levels tended to be younger and to have lower APAP levels on admission. Two patients with acute renal injury died after admission. The other seven patients with renal dysfunction recovered in 2 to 7 days. Six of these received NAC; their mean serum creatinine fell from 3.2 +/- 2.0 versus 1.7 +/- 0.9 mg/dL (p < 0.05). We conclude that acute renal failure is not uncommon in APAP poisoning and appears to be unrelated to the degree of liver injury. NAC therapy did not seem to worsen nephrotoxicity.