Safety and efficacy of oral slow release morphine for maintenance treatment in heroin addicts: a 6-month open noncomparative study

This open-label, noncomparative, single-center trial evaluated the safety and efficacy of once-daily treatment with slow release oral morphine (SROM) capsules for the maintenance treatment of 20 outpatients with heroin dependency over 6 months at the National Institute for Addictions in Sofia, Bulgaria. Doses were individually titrated up to a mean daily maintenance dose of 760 mg (range 440-1,200 mg). SROM was effective in significantly reducing the signs and symptoms of opioid withdrawal and craving for heroin, with stabilization generally evident within two weeks. Nineteen patients completed 6 months of treatment and illicit opioid use was virtually eliminated. One patient withdrew voluntarily at 22 weeks. Validated questionnaires and tests indicated improvements in patients' well-being from baseline assessments. These included significant improvements with regard to suicidal depression (85%), anxiety and dysphoria (66%), general illness (58%), social dysfunction (54%), sense of hopelessness (34%), attention (25%), and self-reported typical depressive (27%) and disease-related (11%) symptoms. No deaths, serious adverse events, or withdrawals due to adverse events occurred. Five episodes of constipation and one episode of sweating (all nonserious and of mild or moderate severity) were reported. Vital signs were unaffected by SROM and no weight change was evident over the study period. The observations made in this study indicate a promising role for once-daily treatment with SROM in the clinical management of heroin dependency.