Opioid Agonist Treatment

Opioid agonist treatment (OAT)—most commonly in the form of buprenorphine/ naloxone or methadone—is an evidence-based treatment for opioid use disorder.

Opioids are substances that bind to and activate (or “turn on”) opioid receptors, providing relief from withdrawal symptoms and cravings in people with an opioid addiction, also know as opioid use disorder. OAT can be understood as a medication used to provide relief from withdrawal symptoms and cravings in people with opioid use disorder. OAT is the recommended first-line treatment for opioid use disorder in British Columbia because it has been shown to be much better than withdrawal management (“detox”) alone in terms of keeping people in treatment, helping them to stop using opioids, and significantly reducing the risk of overdose, blood-borne infections (like HIV or hepatitis C), and death.

Types of OAT

In BC, there are many kinds of OAT that are commonly used (buprenorphine/ naloxone, methadone, and slow release oral morphine).

Buprenorphine/naloxone affords people added flexibility. Unlike methadone, which is the most commonly prescribed OAT in BC, buprenorphine/naloxone has a better safety profile, including much lower risk of respiratory depression and overdose, and can very commonly be prescribed as “take- home” doses. This means that people on buprenorphine/naloxone, once they have stabilized on the medication, can often go to the pharmacy once a week or once every two weeks to receive their medication. Some people on methadone have to go to the clinic every day, while others have to go a few times a week.

Slow-release oral morphine is another kind of OAT used in BC. It is used much less frequently and is generally prescribed for people who tried buprenorphine/naloxone and/or methadone and found they still had cravings and withdrawal symptoms and continued to use illicit opioids. People receiving slow-release oral morphine generally have to go to the pharmacy every day to receive their medication.

PharmaCare covers OAT under the income-based Fair PharmaCare plan for those who qualify, as well as 100% coverage under PharmaCare Plan C (for those on income assistance) and Plan G (for those who demonstrate clinical and financial need for certain psychiatric medications).

Some primary care doctors prescribe buprenorphine/naloxone (also called Suboxone®), while a specialist may need to be seen to be prescribed methadone or slow-release oral morphine. Talk with your doctor to determine if they prescribe these medications.

If your loved one has tried OAT before and not been able to stop using illicit opioids, their doctor might suggest injectable OAT. Injectable OAT is a more intensive treatment program where people go to a clinic or pharmacy up to three times a day to self-administer certain medications (hydromorphone or diacetylmorphine) under supervision. It is very well supported by evidence for people with severe opioid use disorder who have not benefitted from other OAT options.

What to expect with OAT

If your child or loved one has an opioid use disorder, it is likely that they will be offered OAT along with other care that includes provider-led counselling, long-term monitoring of substance use care (to identify relapse and adjust medication dosage as needed), comprehensive preventive and primary care, and referrals to psychosocial treatment interventions and supports.

Some people think that opioid agonist treatments (for example buprenorphine/ naloxone and methadone) are just “substituting one drug for another,” however, as science advances, it has become clear that long-term, unmanaged opioid use disorder causes changes in the brain and body. More and more evidence is showing that the best and safest treatment for opioid use disorder is medication. This allows individuals to stop having to focus all their time and effort (including sometimes turning to crime and other high-risk activities) in order to stop the very painful withdrawal symptoms that emerge if they haven’t taken opioids recently. This also prevents people from having to take risky street drugs that may be tainted with fentanyl and other synthetic opioids.

Other benefits of OAT include connecting individuals to health care and other services, helping bring stability to their lives (which might include housing, employment, or other services), and removing the risk of overdose from street opioids contaminated by fentanyl, carfentanil, and other synthetic opioids.

OAT should be considered a long-term treatment. Studies have found that people have the best outcomes (including the lowest risk of relapse) when they receive OAT for at least one year. Some people will take OAT for a long time, while others may decide with their health care providers that they would like to lower their dose or come off it entirely. It is very important that people work with their prescriber to very slowly taper off of OAT and be monitored for relapse throughout the tapering period.

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