Opioids are medicines chemically related to the compounds found in the opium poppy, a plant that has been used therapeutically for thousands of years. Opioids are commonly used in modern medicine to treat pain. Because they can also create feelings of euphoria, opioids may also be used for recreational or other non-medical purposes. For some people, regular on-going use of opioids may lead to dependence or addiction, for which opioid substitution treatment (OST) is among the most effective medical interventions.
Opioid substitution treatment was first practiced in the early 20th century, when doctors prescribed maintenance doses of codeine, morphine or heroin to patients who were dependent on these drugs. However, law enforcement intolerance for this compassionate approach resulted in the arrest and punishment of physicians. As a result, the medical profession quickly abandoned the practice.
OST was revived in the 1960s when physicians in Vancouver experimented with prescribing oral methadone to patients who were chronic heroin users. In the 1980s, the injection of opioids became a more acute public health concern because of transmittable diseases such as HIV spreading due to needle sharing. Since the 1990s, OST in British Columbia has expanded steadily, and a recent report on HIV by the Office of the Provincial Health Officer indicated that it has contributed to declining rates of HIV among people who inject drugs. Likewise, the World Health Organization has endorsed OST as one of themost promising methods of reducing drug dependence and has included methadone on its list of essential medicines.
Methadone and Suboxone™ are the primary medications used for OST in Canada. For most patients, methadone is successful because it can be taken orally and has a long-lasting effect. Suboxone™ is an alternative to methadone for patients who may have unpleasant side-effects or other medical reasons for not using methadone.
There are several key factors that contribute to the success of OST: it prevents the patient from experiencing withdrawal symptoms, it reduces the physical craving of opioids, and it blocks the feeling of euphoria from illicit opioid use. In addition, OST patients report stability in their daily routines, a reduction of criminal activity, and an increased feeling of safety from the harms associated with illicit drug-seeking, injection and, for some, involvement in the sex trade.
There are many population-level benefits to OST, including the reduction of fatal opioid overdose and the transmission of diseases such as HIV and hepatitis C. Additionally, OST is cost-effective. It is less expensive than untreated opioid dependence, and as part of a well-managed care program, OST can retain patients in treatment and reduce the risk of relapse to non-medical opioid use.
Since its revival as a medical intervention, OST has proven to be both an effective treatment for opioid dependence and an important way to reduce injection drug use and associated risks. In BC, OST is an important part of a comprehensive health system response to opioid dependence, and continual effort is being made to identify areas of improvement in service provision and health outcomes for those who are opioid dependent. Also, new research on OST, including studies conducted in British Columbia, is suggesting that other kinds of opioid medications—including diacetylmorphine and hydromorphone—may be useful alternatives to methadone or Suboxone, especially for patients who do not respond well to other treatments.
Some critics object to maintenance prescribing as a medical practice, suggesting that people with substance dependence problems should not be allowed to continue using any psychoactive substances. However, people with eating disorders are not expected to give up eating food, nor are people with sex addiction necessarily expected to become celibate. In some ways, OST is comparable to nicotine replacement therapy, or the medical use of nicotine-containing skin patch or chewing gum as a replacement for tobacco. Addictions are complex phenomena, and scientific evidence clearly shows that OST can be a valuable therapeutic intervention for people seeking medical help to deal with opioid dependence.
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*Please note that the material presented here does not necessarily imply endorsement or agreement by individuals at the Centre for Addictions Research of BC