An implant to treat people addicted to such drugs as Oxycontin and heroin appears to help addicts cut back on drug use and avoid other problems that often come with other treatments, researchers report.
The implant uses buprenorphine, a medication that has been available in pill form since 2008 in Canada and is related to methadone.
Unlike liquid methadone and pill-form buprenorphine, the implant ensures that addicts can't skip doses or sell their medications on the street. It also means addicts don't have to return regularly to a methadone clinic for soes.
The implant is a three-centimetre-long rod that sits just underneath the skin of the arm. Over six months, the implant releases a steady stream of buprenorphine, decreasing cravings and reducing withdrawal symptoms without offering the euphoria that comes from heroin and OxyContin abuse.
The implant, called Probuphine, is being developed by U.S.-based Titan Pharmaceuticals Inc. The drug requires further testing and government approval before it would be available for patients.
Results of a study to test the implant were published this week in JAMA, the Journal of the American Medical Association.
The study included 163 opioid addicts; 108 got the implants while 55 received placebo implants. Drug counselling was also provided to all patients, and their street drug use was measured by urine samples.
During the 10-month long study, the buprenorphine implant group had significantly more urine samples that tested negative for illicit opioids during weeks 1 through 16: around 40 per cent compared to 28 per cent in the placebo group.
As well, 66 per cent of patients in the buprenorphine implant group stayed in the study for the full 24-week study period compared to just 31 per cent of those in the placebo group.
No patients in the buprenorphine implant group met the definition of treatment failure; 30.9 per cent of placebo patients were classified as treatment failures.
The patients also reported fewer withdrawal symptoms and lower ratings of cravings.
Dr. Walter Ling, a professor of psychiatry and director of the Integrated Substance Abuse Programs at UCLA and the paper's lead author, said in Titan Pharmaceuticals news release that "the introduction of buprenorphine into clinical practice is arguably the most significant improvement in the treatment of opioid addiction in the last decade."
Opioid dependence is a growing health concern. The World Health Organization estimates that 2.8 million people in Europe and the United States are addicted to opiates such as heroin.
Canadians rank third in the world in the use of prescription opioids, just behind the U.S. and Germany, statistics show.
In an editorial accompanying the study, Dr. Patrick O'Connor of the Yale University School of Medicine, says the study findings represent a potentially important step forward in treating opiate dependence.
"If further research suggests that this buprenorphine implant is as good as or better than current treatment approaches," O'Connor writes, "then the study ... would represent a major advance in the substantial and continued progress that has occurred in the treatment of opioid dependence since methadone maintenance began in the 1960s."
