Severe acetaminophen hepatotoxicity frequently leads to acute liver failure.
Dr Anne Larson and colleagues determined the incidence, risk factors, and outcomes of acetaminophen-induced acute liver failure.
The investigative team gathered prospective data from 662 patients at 22 tertiary care centers in the United States over a 6-year period.
The patients fulfilled standard criteria for acute liver failure including coagulopathy and encephalopathy.
Of these, 42% were determined to result from acetaminophen liver injury.
The annual percentage of acetaminophen-related acute liver failure rose during the study from 28% in 1998 to 51% in 2003.
The team reported that the median dose ingested was 24 g.
|81% were taking acetaminophen and/or other analgesics
The investigators found that unintentional overdoses accounted for 48% of cases, intentional for 44%, while 8% were of unknown intent.
In the unintentional group, 38% took 2 or more acetaminophen preparations simultaneously.
The team noted that 63% used narcotic-containing compounds.
A further 81% of unintentional patients reported taking acetaminophen and/or other analgesics for acute or chronic pain syndromes.
Overall, 65% survived, 27% died without transplantation, and 8% underwent liver transplantation.
The investigators observed that 71% were alive at 3 weeks.
Furthermore, the team observed that transplant-free survival rate and rate of liver transplantation were similar between intentional and unintentional groups.
Dr Larson's team concluded, “Acetaminophen hepatotoxicity far exceeds other causes of acute liver failure in the United States.”
“Susceptible patients have concomitant depression, chronic pain, alcohol or narcotic use, and/or take several preparations simultaneously.”
“Education of patients, physicians, and pharmacies to limit high-risk use settings is recommended.”