Letters to the Editor
Naltrexone and liver disease
- Mike McDonough, Philip Crowley
- Aust Prescr 2015;38:151
- 1 October 2015
- DOI: 10.18773/austprescr.2015.063
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In the good review on long-term drug treatment of patients with alcohol dependence (Aust Prescr 2015;38:41-3), the important issue of underuse of pharmacotherapy for alcohol dependence is identified and an outline of treatment is given. However, the article states that naltrexone is contraindicated in acute hepatitis or liver failure. In my clinical practice, varying degrees of chronic liver disease are commonly encountered when treating an alcohol-dependent population. Continued heavy drinking is much more likely to pose a greater risk to liver function than naltrexone. Arguably, the risk−benefit assessment likely favours naltrexone treatment. Naltrexone can be prescribed in patients with stable or compensated cirrhosis but is not recommended in acute liver failure. It carries a low risk of hepatotoxicity. However, in my experience, many potentially suitable patients are not given the drug because of concerns about hepatotoxicity.
Western Health, Melbourne
Philip Crowley, the author of the article, comments
Precautions listed in naltrexone’s product information include saying it may cause hepatocellular injury when given in excessive doses, and its use in patients with active liver disease must be carefully considered in light of its hepatotoxic effects. The product information also states that naltrexone is contraindicated in acute hepatitis or liver failure. This is based on a study in which 300 mg/day naltrexone was administered to obese patients. Five of 26 naltrexone recipients, and none of the placebo group, developed elevated serum transaminases after 3−8 weeks of treatment.1
Data on aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been used as an indicator of hepatotoxicity, with concentrations indicating both the effects of medication on hepatotoxicity, and reduced hepatotoxicity due to reduced alcohol consumption. Twelve of 1383 participants (0.9%) in the COMBINE study2 had elevated liver enzymes greater than five times the upper levels of normal. (Most cases were in the naltrexone group.) These effects resolved following discontinuation of the drug. This is the one study large enough to detect an adverse effect at this low level of incidence.
I agree that often patients do better in a risk−benefit assessment when taking naltrexone compared to not taking it (because of concerns about minor liver enzyme changes).
Addiction Medicine, Western Health, Melbourne
Addiction medicine specialist