Opioid-related mortality and filled prescriptions for buprenorphine and methadone.

INTRODUCTION AND AIMS

To assess opioid-related mortality and correlation with filled prescriptions for buprenorphine and methadone.

DESIGN AND METHODS

A register study, including data from the Swedish Forensic Pathology and Forensic Toxicology databases 2003-2010, the Prescribed Drug Register and the National Patient Register.

RESULTS

A total of 1301 deaths, assessed as related to buprenorphine, methadone or heroin, or a combination of them, were studied. The largest number of fatalities was related to intake of heroin (n = 776), followed by methadone (n = 342) and buprenorphine (n = 168). The total annual number of fatal cases related to the studied drugs more than doubled (116 to 255) during the study period. There were increases in mortality related to both buprenorphine and methadone: from 1 to 49 cases for buprenorphine, and from 19 to 81 cases for methadone. Only one-fifth of the fatal cases had a filled prescription for the maintenance drug assessed as the cause of death.

DISCUSSION AND CONCLUSION

This study showed that most fatalities were not related to filled prescriptions of maintenance drugs, and a substantial illicit use of buprenorphine and methadone resulting in deaths was revealed. To prevent opioid toxicity deaths it is important to make efforts not only to reduce drug diversion from maintenance programs, but also to improve the control of drug trafficking and other illegal sources.