UT Southwestern Study Finds Common Pain Reliever Can Cause Liver Damage, Especially Mixed With Alcohol

Dr. William Lee, professor of internal medicine, and his team ofliver-disease researchers reviewed the records of 589 patients who overdosed ondrugs and were treated at Dallas County's Parkland Memorial Hospital from 1992to 1995. From that group he found 71 patients who were hospitalized with liverdamage after taking acetaminophen, the most common cause of acute liver failure.

Twenty-one patients in this group accidentally took an overdose of thecommon pain reliever, and in 13 of these alcohol was a factor in the toxicreaction. The other 50 in the group took an overdose of acetaminophen inattempts to commit suicide; 10, who also had consumed alcohol, experiencedsignificant liver injury.

Surprisingly, accidental overdoses compared to suicidal overdoses ofacetaminophen were more often fatal even though the amounts taken were lower.The median dose of an accidental overdose was 11 grams, and it proved fatal forfour patients. The median dose of a suicide attempt was 24 grams and provedfatal to one of the patients studied. Acetaminophen was found to be the mostcommon cause of acute liver failure during the study period.

Liver injury resulting from suicidal intent is common in the UnitedKingdom, but in the United States it is more prevalent among alcoholic orfasting patients, who ingest smaller quantities of acetaminophen for pain reliefonly, Lee said.

"Our study suggests we should be more diligent in educating the publicand physicians about the risks associated with acetaminophen because it'scommonplace for people to reach for a bottle of pain reliever without thinkingabout possible complications," said Lee, who directs the Liver Diseases ClinicalCenter atUT Southwestern's James W. Aston Ambulatory Care Center.

Lee speculates that acetaminophen causes liver damage in alcoholic orfasting patients because alcohol and fasting deplete the body of glutathione, adetoxification agent normally found in large quantities in the liver.

He cautions that even people who aren't alcoholics but consume alcoholbefore or after taking acetaminophen can experience liver damage.

"In light of these findings, I think we should use this study not as acondemnation of over-the-counter pain relievers that contain acetaminophen butas a means to educate people that these drugs should be used responsibly," Leesaid.

The majority of patients Lee studied purposefully or inadvertently tookamounts far greater than the 4 grams (eight tablets) per 24-hour limit listed onthe packages of most brands.

Other findings of the study:

• Suicidal patients tended to be younger than those in the accident group;

• The suicidal group included more whites and Asians, while the accidental group

  predominantly consisted of African-Americans and Hispanics;

• Women outnumbered men in both groups, especially in the suicidal group, whichhad a nearly 3-to-1 female-to-male ratio;

• Among the accidental toxicity group, reasons for using acetaminophen for painrelief included abdominal pain, toothache, headache, hip pain and flu-likesymptoms.