Economic evaluation of Suboxone® for substitution treatment of opioid drug dependence in Portugal

Background: According to a recent Portuguese study the prevalence of lifetime consumption of heroin in the global population (age range: 15-74 years) is 0.5%. Methadone is the standard pharmacological treatment, while buprenorphine has been available since 1999 as an alternative treatment. Nevertheless, no comparative economic evaluation of the cost-effectiveness of these therapies has been made available. Aim: This study estimates the cost-effectiveness and cost-utility of a fixed dose combination of buprenorphine-naloxone (BIN) versus methadone as substitution treatments for opioid drug dependence from the Portuguese social perspective. Material and Methods: The comparator for BIN was methadone treatment, which is the most common pharmacological therapy and current clinical practice in Portugal. Health gains were measured using the number of heroin-free days per year (indicator of effectiveness) and quality-adjusted life years (QALYs) associated with each treatment. Estimated costs included acquisition, preparation and transport of medication; costs of dispensing and supervision of administration; costs arising from the periodic monitoring of patients and the non-medical direct costs of crime associated with drug addiction. Results: The BIN combination is associated with an incremental cost-utility ratio of (sic)5,914 per QALY gained. The BIN combination is dominant when the analysis includes costs of crime associated with drug addiction. Conclusions: The results suggest that this combination is cost-effective and has the potential to generate health gains in the target population at a low cost.