New methadone formulation in France: results from 5 years of utilization.

BACKGROUND In France, methadone has historically been less accessible than buprenorphine. In 2008, a dry formulation (capsule) was introduced into the market, aimed in particular to improve methadone accessibility. OBJECTIVE To describe the impact (prevalence of use, patient profiles and compliance with requirements) of the dry methadone formulation in France. METHOD A retrospective cohort (from 2008 to 2012) was created from the data of the French General Health Insurance System which covers 80% of the French population. For each years, all subjects affiliated to this insurance system in southeast France (about 8.5 million inhabitants) with at least two reimbursements of methadone between 1st January and 31st December were selected. RESULTS In 2012, the proportion of capsule users was almost the same as that of syrup users (40.0% versus 43.1%; p < 0.001). The rise in the number of methadone users has followed the rise in capsule users. Over the study period, the proportion of patients using benzodiazepines or antidepressants was 6-9% (p < 0.001) higher for capsule users than for syrup users. On average over the study period, 18% of subjects had at least one concurrent issue of the two forms. CONCLUSION The study has shown the rapid spread of the capsule formulation among methadone users. This may suggest that the capsule is well accepted by patients and the medical community. However, the monitoring of methadone-related deaths should continue because of the pharmacodynamic properties of methadone and the context of relaxed regulations concerning access to methadone maintenance treatement (MMT).