Comparative study of the effectiveness of slow-release morphine and methadone for opioid maintenance therapy

Slow-release morphine may represent a much-needed new pharmacological treatment for opioid dependence.

In a 14-week randomized, double-blind, double-dummy, cross-over study oral slow-release morphine was compared with methadone as a treatment for opioid dependency. During two study periods, each consisting of a 1-week titration and a 6-week fixed-dose treatment phase, medication was administered daily under supervised conditions.

The study was carried out at the Addiction Clinic, Department of Psychiatry, Medical University Vienna.

Sixty-four subjects (56 males, eight females) with opioid dependence participated in the trial.

Efficacy was evaluated on the basis of retention, use of illicit substances based on urinalysis, extent of drug cravings, withdrawal symptoms and general wellbeing. Safety was assessed on the basis of adverse events and clinical and physical examination. Demographic and baseline characteristics were assessed using the European Addiction Severity Index.

Fifty-five patients (86%) completed the study, with a mean methadone dose of 85 mg and a mean slow-release morphine dose of 680 mg. No significant differences in retention or use of illicit substances (opioids, benzodiazepines, cocaine) were observed, irrespective of treatment group or medication. However, patients receiving slow-release morphine had significantly lower depression (P < 0.001) and anxiety scores (P = 0.008) and fewer physical complaints (P < 0.001).

Oral slow-release morphine is as effective as methadone in the treatment of opioid dependency, with comparable safety and tolerability and a greater benefit on patient wellbeing. Greater pharmaceutical diversity represents a modern development in mainstream medicine. Slow-release morphine might represent a future treatment option that will improve long-term outcomes for this target group.