Risperidone opioids

Two patients who were hospitalized with a diagnosis of opioid dependence received concomitant treatment with methadone 50 mg/day in one case, and levorpha-nol 14 mg/day in the other, each in association with risperidone. After several days, both had symptoms of opioid withdrawal despite having no change in their opioid doses (256). The withdrawal symptoms resolved soon after risperidone was withdrawn. According to the authors, this finding suggests that risperidone may precipitate opioid withdrawal in opioid-dependent patients. 

Wines JD Jr, Weiss RD. Opioid withdrawal during risperidone treatment. J Clin Psychopharmacol 1999 19(3) 265-7. 

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