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Letter to the editor

Editor, – I refer to the comment on naltrexone published recently in your 'New drugs' section (Aust Prescr 1999;22:45-6).

Opiate and alcohol dependencies are complex disease states. Successful management requires both medical and psychosocial interventions. Therefore naltrexone should be considered as only one of many factors determining the success of treatment. There is clinical evidence1 to support the efficacy of naltrexone when used in conjunction with psychosocial therapy in the maintenance treatment of opiate dependence. Relapse rate should not be considered as the only evidence of efficacy, which should also include decrease of craving, and reduction of heroin taking during treatment. There is substantial evidence that naltrexone reduces alcohol craving, supports abstinence, prevents relapse and decreases alcohol consumption.

I would like to put the statement 'the drug can damage the liver', into perspective. Elevations of liver enzymes were observed previously in patients participating in studies to evaluate high doses of naltrexone (up to 300 mg/day) as a potential treatment of obesity or dementia.2,3,4,5 However, in recent studies in which naltrexone was administered at recommended dosages to patients with alcohol dependence, hepatotoxicity was not identified as a concern.6 Nevertheless, the product information for naltrexone contains a caution of the potential risk of hepatocellular injury when given in excessive doses. It also states that evaluations using appropriate batteries of tests to detect hepatic injury are recommended at a frequency appropriate to the clinical situation and the dose of naltrexone. Naltrexone does not appear to be a hepatotoxin at the currently recommended doses.

Gennaro D'Alesandro
Product Manager
Orphan Australia
Berwick, Vic.

References

  1. Judson BA, Carney TM, Goldstein A. Naltrexone treatment of heroin addiction: efficacy and safety in a double-blind dosage comparison. Drug Alcohol Depend 1981;7:325-46 .
  2. Berke LK, Drake CR, Bibbs ML, Williams FL, Kaiser DL. Effects of long-term therapy with naltrexone on body weight in obesity. Clin Pharmacol Ther 1985;38:419-22. .
  3. Malcolm R, O'Neil PM, Sexauer JD, Riddle FE, Currey HS, Counts C. A controlled trial of naltrexone in obese humans. Int J Obes 1985;9:347-53. .
  4. Levine AS, Hatsukami D, Gannon M, Pfohl D. High-dose naltrexone therapy and dietary counseling for obesity. Biol Psychiatry 1987;22:35-42. .
  5. Pfohl DN, Allen JI, Knopman DS, Malcolm RJ, Atkinson RL, Mitchell JE. Naltrexone hydrochloride (Trexan): a review of serum transaminase elevations at high dosage. NIDA Res Monogr 1986;67:66-72 .
  6. The safety profile of naltrexone in the treatment of alcoholism. Results from a multi center usage study. Arch Gen Psychiatry 1997;54:1130-5 .