[Therapeutic response in outpatient opioid substitution treatment]

The aim of the study was to compare the success of buprenorphine therapy induction between two groups of outpatients.

The analysis was retrospective, based on medical documentation from the Centre for Prevention of Drug Addiction, Public Health Institute of the Split-Dalmatia County, Split, Croatia. The success of buprenorphine treatment induction and maintenance was compared between two groups of outpatients treated in 2006 (group 1, n=24) and 2007 (group 2, n=28), observed for the first four months of both years and only patients that presented to the Centre once a week for at least one month were included. The dose of buprenorphine was 2-4 mg per day in group 1 and 6-8 mg per day in group 2. Between group differences were compared using chi2-test with Yates correction and Mann-Whitney U-test. The probability value of P<0.05 was considered significant.

There was no significant difference between groups in demographic characteristics (sex, age, employment, education and marital status) and duration of heroin use. In group 1, 12 (50%) patients continued buprenorphine substitution treatment after 30 days, whereas in group 2 this figure was 21 (75%) patients (P<0.05). A significant difference between groups was also recorded in positive urine opiate test in the first and second week (P<0.05).

Pharmacotherapy alone is rarely sufficient treatment for drug addiction, but it is an essential part of opioid substitution treatment. Therefore it is important to recommend an adequate dose of agonist or agonist/antagonist medication. As the cost of buprenorphine therapy has been reimbursed by the Croatian Health Insurance Institute in full amount since the beginning of 2007, a higher ("adequate") dose of buprenorphine is recommended to improve the success of buprenorphine treatment induction and maintenance.