The meta-analysis by Srisurapanont and Jarusuraisin (26) included a total of 2,861 subjects from 24 randomized, controlled trials. In the short term, naltrexone significantly decreased risk of relapse to heavy drinking (relative risk [RR] 0.64, 95% CI 0.51 to 0.82) but did not reduce the likelihood of a return to any drinking (RR 0.91, 95% CI 0.81 to 1.02). Treatment with naltrexone significantly increased adverse effects, roughly doubling the likelihood of reports of nausea and dizziness and increasing the risk of fatigue by about one-third compared with placebo. However, naltrexone treatment did not significantly affect the rate of premature discontinuation of treatment (RR 0.85, 95% CI 0.70 to 1.01). Follow-up studies of patients treated with naltrexone or placebo for 12 weeks (22,27) or 4 months (28) have shown that the medication group differences are no longer significant at posttreatment follow-up. These findings suggest that treatment with naltrexone is warranted for longer than 4 months, though the optimal duration of treatment is unknown. An alternate approach to the use of naltrexone based on its efficacy in reducing the risk of heavy drinking among patients who continue to drink was evaluated in a study that compared the effects of naltrexone 50 mg with those of placebo in an 8-week study of problem drinkers (29). In this study, patients were randomly assigned to receive study medication either on a daily basis or for use targeted to situations identified by the patients as being high risk for heavy drinking (with the number of tablets available for use by patients in the targeted conditions decreasing over the course of the trial). Irrespective of whether they received naltrexone or placebo, patients who were trained and encouraged to use targeted treatment showed a reduced likelihood of any drinking. There was also a 19% reduction in the likelihood of heavy drinking with naltrexone treatment, suggesting that naltrexone may be useful in reducing heavy drinking, among patients who want to reduce their drinking to safe levels.
References
Ries, Richard, Shannon C. Miller, Richard Saitz, and David A. Fiellin, eds. 2014. The ASAM principles of addiction medicine. Fifth edition. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins.