The National Treatment Agency has set 12-week retention as an outcome measure for the treatment of opiate addiction. Both methadone and buprenorphine show research evidence of efficacy in this condition. To ensure that these medications are being used optimally, we performed a baseline audit in two drug treatment services in North East London with a view to identifying potential improvements in service delivery.

Prescriptions for patients being treated for opiate addiction have been generated from a computerised system since April 2004. We obtained a list of all prescriptions generated between April 2004 and August 2005. As well as demographic data, we noted what medication had been prescribed, the daily dose at stabilisation, and whether the patient was still in treatment at 12 weeks.

214 patients received 226 episodes of treatment. 114 episodes involved treatment with methadone, 112 with buprenorphine. 69% of episodes in which a patient was treated with methadone (mean daily dose 51mg) were associated with still being in treatment at 12 weeks; the figure for buprenorphine was 43%, with a mean daily dose of 11mg.

Methadone currently seems to be associated with better retention than buprenorphine, though some guidelines suggest that the dose of buprenorphine is too low. Other guidelines suggest that increasing the dose of methadone has potential for a small additional improvement in retention. We aim to get daily doses of methadone to a mean of 60mg, buprenorphine to 16mg, and will re-audit.