Sulindac hepatotoxicity: a case report and review

Mutation of TGFβ-RII eliminates NSAID cancer chemoprevention

Non-steroidal anti-inflammatory drugs (NSAIDs) exhibit anti-neoplastic (chemoprevention) activity for sporadic cancers and the hereditary cancer predisposition Lynch syndrome (LS/HNPCC). However, the mechanism of NSAID tumor suppression has remained enigmatic. Defects in the core mismatch repair (MMR) genes MSH2 and MLH1 are the principal drivers of LS/HNPCC. Previous work has demonstrated that the villin-Cre^+/−Msh2^flox/flox (VpC-Msh2) mouse is a reliable model for LS/HNPCC intestinal tumorigenesis, which is significantly suppressed by treatment with the NSAID aspirin (ASA) similar to human chemoprevention. Here we show that including a TGFβ receptor type-II (Tgfβ-RII) mutation in the VpC-Msh2 mouse (villin-Cre^+/−Msh2^flox/floxTgfβ−RII^flox/flox) completely eliminates NSAID tumor suppression. These results provide strong genetic evidence that TGFβ signaling and/or effectors participate in NSAID-dependent anti-neoplastic processes and provide fresh avenues for understanding NSAID chemoprevention and resistance.

Does therapeutic use of acetaminophen cause acute liver failure?

STUDY OBJECTIVE

To compare the reported occurrence of liver failure in subjects in prospective trials with that in patients in retrospective reports after repeated use of therapeutic dosages of acetaminophen.

DESIGN

Systematic review of the medical literature.

DATA SOURCE

MEDLINE and EMBASE biomedical and pharmacologic databases.

SUBJECTS

Adults who received repeated dosing of acetaminophen 4 g/day or lower for at least 24 hours.

MEASUREMENTS AND MAIN RESULTS

Articles written in several languages were abstracted by trained personnel using a structured abstraction form. Data were categorized by methodology (prospective vs retrospective), acetaminophen dosage, and type of liver effect. A total of 791 articles were identified, which included 30,865 subjects in prospective studies and 9337 patients in retrospective reports. The prospective studies reported no cases of fulminant hepatic injury, liver transplantation, or death due to acetaminophen. Of the 30,865 subjects in these studies, 129 (0.4%) were identified who had a serum aminotransferase level that exceeded the upper limit of normal, including 61 subjects in randomized trials in which the proportion of serum aminotransferase level increase was the same as or less than that in the placebo group and 68 subjects in trials without a placebo group. In addition, 4263 (13.8%) received the maximum recommended therapeutic dosage (3.9-4 g/day). In the retrospective reports, 96 patients (1.0%) had a serum alanine aminotransferase level that exceeded the upper limit of normal, one (0.01%) underwent liver transplantation, and six (0.06%) died. Causality relationship of acetaminophen for each retrospective case was assessed with the Naranjo adverse drug reaction probability scale. The mean +/- SD Naranjo score for all 103 retrospective cases was 3.2 +/- 1.9, indicating a possible relationship between the increased aminotransferase levels and acetaminophen use. Some retrospective reports contained information suggesting that the patient had ingested an overdose despite a history of therapeutic use.

CONCLUSION

Prospective studies indicated that repeated use of a true therapeutic acetaminophen dosage may slightly increase the level of serum aminotransferase activity, but hepatic failure or death was not reported. Retrospective reports indicated a higher rate of increased serum aminotransferase levels, and several reported associated liver injury and death. The differing results and presence of evidence indicating inaccurate acetaminophen dosage information in some case reports suggests that these cases may be inadvertent overdoses, rather than true therapeutic dosages.

Update: the clinical importance of acetaminophen hepatotoxicity in non-alcoholic and alcoholic subjects

Acetaminophen (paracetamol) is one of the most commonly used over-the-counter medications. Taken in doses greater than 150 mg/kg/day (>10 g), it usually causes acute liver failure. The authors review mainly the management of acetaminophen toxicity in both users and nonusers of alcohol. Chronic alcoholics are a special subgroup, who risk serious toxicity when taking acetaminophen, even in therapeutic doses. The acetaminophen-alcohol interaction is complex, because acute and chronic ethanol have opposite effects. This review also considers physiological and clinical changes, as well as the diagnosis and treatment of acetaminophen poisoning.

Drug-induced cholestasis

Acute, drug-induced hepatocellular cholestasis (either pure or cholestatic hepatitis) is a common manifestation of drug-induced hepatic injury. The drugs most frequently responsible are hormonal steroids and psychopharmacological agents (in particular phenothiazines and some antidepressants). Cholestasis usually subsides without sequelae in less than six months. Acute, drug-induced ductular cholestasis is uncommon and can resemble biliary tract obstruction. Complete recovery occurs promptly after the withdrawal of the causative drug in most cases. The pathogenetic mechanism may be immunoallergic. Prolonged ductular or ductal cholestasis can follow drug-induced acute hepatitis despite prompt withdrawal of the offending drug. This syndrome, observed mainly with chlorpromazine and uncommonly with twenty other drugs, is characterized by the progressive disappearance of small bile ducts and by manifestations mimicking primary biliary cirrhosis. However, its prognosis appears to be better than that of primary biliary cirrhosis, the condition being reversible in the majority of cases or even subsiding completely. The mechanism is still unknown, but several features suggest some form of autoimmunity. Extrahepatic cholestasis related to sclerosing cholangitis is a frequent and long-term complication of intra-arterial infusion of floxuridine in patients treated for hepatic metastases from colorectal carcinoma. Although it may be reversible, floxuridine-induced sclerosing cholangitis has a poor prognosis and can lead to death in a few patients. The mechanism is probably related to the vascular supply of the common hepatic duct and its relationship to the perfusion territory of floxuridine.