The rapid scale up of opioid substitution treatment (OST) for drug users mainly achieved through the possibility of prescribing buprenorphine in primary care has been successful in reducing HIV prevalence among drug users but still inadequate for reducing the spread of HCV. To date, methadone in France can only be initialised in drug centres but GPs can prescribe methadone after stabilisation of dosages.

This study was born as an answer to a request from the French Minister of Health that supports the initialisation of methadone in primary care in order to improve coverage by OST (now 70%) in drug users.

We aimed to test the non inferiority of the proportion of non users of street-opioids after one year of treatment in patients inducted in primary care (PC) vs.those inducted in a specialised center for substance dependence (CSAPA).

In this multisite, open-label, randomised controlled non-inferiority trial, opioid dependent individuals were randomized to start methadone either in PC or in a CSAPA. After stabilization of methadone dosage (~2 weeks), patients could change arm. Follow-up assessments through medical questionnaires and phone interviews was scheduled at month 0 (M0, enrolment) M3, M6, M12. The opiate treatment index (OTI) was used for computing the proportion of patients reporting no use of street opioids in the last month at M12 (primary outcome) in those inducted in PC or in a CSAPA and the non inferiority margins.

Primary analysis was by intention to treat (ITT)

Inclusion Criteria:

• 18 to 70 years patients needing methadone for their opioid dependence who are either naives of methadone treatment (prescribed) since at least 1 month
• need to switch from buprenorphine to methadone treatment
• negative test for pregnancy

Exclusion Criteria:

• co-dependent on alcohol and benzodiazepines,
• inmates,
• pregnant women,
• individual in irregular situation or who cannot be joined by phone.