Opioid antagonists in the treatment of impulse-control disorders

Background: Symptoms of impulse-control disorders are generally refractory to psychotherapeutic or pharmacologic treatments. Recent study results suggest that opioid antagonists may reduce human urges, one of the core symptoms of impulse-control disorders. The author discusses the rationale for and the potential utility of the opioid antagonists in the treatment of impulse-control disorders. Method: Work by preclinical and clinical investigators on the subject of motivation and its contextually relevant behavior is reviewed. The review includes the pharmacologic modulation of the motivation or drive and subsequent changes in behavior in animals and humans. On the basis of these reviews, the author prescribed naltrexone for up to 9 months to 15 patients who had impulse-control disorder, and 3 select cases are reported. Results: Naltrexone was generally well tolerated, and there were no hepatic side effects. Naltrexone appears to reduce urge-related symptoms and decreases the problematic behaviors such as pathological gambling. The effect appears to be sustained. In general, 50 mg/day of naltrexone was not effective. Most patients required higher doses. Results were similar in the 12 other cases not reported here. Conclusion: Naltrexone may be of use in select impulse-control disorder patients. Other opioid antagonists such as nalmefene also need to be tested. Until controlled study data become available, the present report should be viewed as preliminary.