Slow-release oral morphine for maintenance treatment of opioid addicts intolerant to methadone or with inadequate withdrawal suppression


Andrej Kastelic, Centre for Treatment of Drug Addiction, Psychiatric Clinic Ljubljana, Zaloska 29, SI-1000 Ljubljana, Slovenia. E-mail:


Aims  Evaluation of the efficacy, safety and acceptability of slow-release oral morphine (SROM) in opioid addicts intolerant to methadone or with inadequate withdrawal suppression.

Design  Prospective, open, non-comparative multi-centre study.

Setting  Twelve out-patient Centres for Prevention and Treatment of Drug Addiction in Slovenia.

Participants  Male and female opioid addicts (age >18 years) under methadone maintenance therapy requiring a change of treatment in order to continue more effectively with maintenance.

Interventions  Maintenance therapy with methadone was switched to once-daily SROM.

Measurements  Efficacy evaluations were based on the reduction of side effects and on the degree of suppression of opiate craving, signs and symptoms of withdrawal. In addition, self-reported somatic and psychic symptoms (SCL-27) as well as World Health Organization quality of life-related (WHO QOL) parameters were monitored.

Findings  Thirty-nine subjects intolerant to methadone and 28 subjects showing inadequate withdrawal suppression under methadone ≥90 mg/day were included as two separate groups in the efficacy analyses. Treatment was switched easily from methadone to SROM on a 1 : 8 ratio. Four-week SROM treatment resulted in significant reduction of side effects reported under methadone. Signs and symptoms of opioid withdrawal as well as craving for opiates were improved significantly in patients with inadequate response to methadone. Physical and psychological wellbeing improved significantly under SROM treatment. SROM was tolerated very well.

Conclusions  Maintenance treatment with SROM appears to be a clinically useful alternative treatment in subjects not tolerating methadone or with inadequate withdrawal suppression.