Motivation for treatment predict adherence to treatment in a randomised clinical trial

The most beneficial intervention for the treatment of opioid dependence is opioid substitution maintenance treatment with full opioid agonist methadone, or partial agonist buprenorphine / buprenorphine-naloxone. Low motivation is related to poor performance during treatment and after treatment outcomes. Awareness of the patients’ motivation may help clinicians plan the treatment accordingly. Rather few studies have explored the initial motivation for opioid abstinence that influences both the adherence and outcome of opioid-receptor antagonist naltrexone. It is an alternative for patients who are motivated to withhold from opioids use or in countries were substitution therapy is not available. In this study, we investigated the patients’ motivation for and adherence to a new treatment approach to opioid dependence in Europe, namely extended-release naltrexone in comparison to daily oral buprenorphine-naloxone.

Methods

This is an open labeled 12 weeks randomized controlled trial and 36 weeks follow-up study. Before inclusion into the study, participants were referred to a detoxification unit for screening. The study took place in an outpatient setting. Opioid dependent (DSM-IV criteria) men and women between 18 and 60 years old were eligible for participation. Those with serious somatic and psychiatric illness, and alcohol dependence were excluded. Pregnant or breastfeeding women were not included and those of childbearing age should have used birth control.

Interventions

A pre-screening questionnaire, created especially for this study, was distributed by personnel at the opioid maintenance treatment sites, long-term treatment facilities for illicit drug users, centers for individuals with drug problems, prisons, and through addiction consultants at the social offices. Questionnaire was used to examine the level of interest in opiate blocking treatment with extended-release naltrexone and in receiving such treatment in the near future. Individuals recruited to the study filled out the questionnaire before entering the study. At inclusion and every fourth week the study personal collected data on drug use, physical and mental health, social relations, and work status using the European version of the Addiction Severity Index.

Results 159 participants were randomized and 105 completed the trial. In open-arm follow-up study 117 participants were enrolled and 58 completed the 36 weeks. Preliminary results.