Acute renal failure due to acetaminophen ingestion

Acetaminophen is the most commonly reported drug overdose in the United States. Acute renal failure occurs in less than 2% of all acetaminophen poisonings and 10% of severely poisoned patients. At the therapeutic dosages, acetaminophen can be toxic to the kidneys in patients who are glutathione depleted (chronic alcohol ingestion, starvation, or fasting) or who take drugs that stimulate the P-450 microsomal oxidase enzymes (anticonvulsants). Acute renal failure due to acetaminophen manifests as acute tubular necrosis (ATN). ATN can occur alone or in combination with hepatic necrosis. The azotemia of acetaminophen toxicity is typically reversible, although it may worsen over 7 to 10 days before the recovery of renal function occurs. In severe overdoses, renal failure coincides with hepatic encephalopathy and dialysis may be required. Recognition of acetaminophen nephropathy requires the following: (1) a thorough drug history, including over-the-counter medications such as Tylenol or Nyquil; (2) knowledge of the risk factors that lessen its margin of safety at therapeutic ingestions, i.e., alcoholism; and (3) consideration of acetaminophen in the differential diagnosis of patients who present with combined hepatic dysfunction and ATN.