What the Science Says is a series of posts highlighting the latest research from scientists here at the BC Centre on Substance Use (BCCSU). It features summaries of new publications from the BCCSU’s investigators, as well as links out to companion resources that you can consult if you’d like to learn more. With What the Science Says, we aim to keep you — journalists, researchers, members of the public — informed about research coming out of the substance use field in British Columbia.
Connecting people to and retaining them on effective treatments for opioid use disorder has been a longstanding challenge, and promises to become more critically important in the context of the COVID-19 pandemic, as the street drug supply is likely to become even more volatile. This month, we take a look at new research on the treatments that are currently available to people with opioid use disorder, and the current barriers experienced in scaling up access to them.
Wilson, T., Brar, R., Sutherland, C., & Nolan, S. (2020). Use of a primary care and pharmacy-based model of injectable opioid agonist treatment for severe opioid use disorder: a case report. Canadian Medical Association Journal, 192(5), E115-E117.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7004215/ (Open access)
This is a short case report on a patient with treatment-resistant opioid use disorder in Vancouver, British Columbia, written by BCCSU researchers Drs. Tyler Wilson, Rupinder Brar, Christy Sutherland and Seonaid Nolan. The patient was started on hydromorphone (a form of injectable opioid agonist treatment, or iOAT), and continued to access it through his primary care provider and pharmacist, who also monitored his progress on the therapy. Within one month, the patient was stable on iOAT and was able to stop using illegal drugs and his involvement in crime, and transition into stable housing and employment. The patient wished to transition to oral OAT after three months in order to facilitate employment. He relapsed to fentanyl use shortly afterward, and at the time of writing, was again being initiated on iOAT. The study underscores the need to improve access to evidence-based addiction treatments for opioid use disorder, like iOAT. Allowing for the provision of iOAT in primary care clinics and designated pharmacies could be an efficient and cost-effective way of improving access to this service.
Socias, M. E., Dong, H., Wood, E., Brar, R., Richardson, L., Hayashi, K., Kerr, T., & Milloy, M. J. (2020) Trajectories of retention in opioid agonist therapy in a Canadian setting. International Journal of Drug Policy, 9(77).
https://www.ncbi.nlm.nih.gov/pubmed/32050143
This study by BCCSU researchers looked at patterns of opioid agonist treatment (OAT) initiation and retention among a group of people in Vancouver, British Columbia. At the time of the study, most patients were on methadone and were required to visit a health facility (eg. a pharmacy or health clinic) frequently, sometimes on a daily basis, to take their medication. The study identified that employed individuals had more challenges receiving medication daily, suggesting daily witnessed ingestion of medications may be impractical for those who are employed. The study also found that people who started OAT after 2014 were more likely to discontinue their treatment regimen. Around the same time, changes were made to the provincial OAT program, including switching the available methadone formulation. These changes may have played a role in patient adherence to OAT. The authors suggest that further exploration is warranted to review the effects of these policy changes.
Caulfield, M. D. G., Brar, R., Sutherland, C., & Nolan, S. (2020). Transitioning a patient from injectable therapy to sublingual buprenorphine/naloxone for the treatment of opioid use disorder using a microdosing approach. BMJ Case Reports, 13.
https://casereports.bmj.com/content/13/3/e233715
Canadian national guidelines encourage buprenorphine/naloxone or methadone as first-line treatment options for opioid use disorder (OUD). If these oral treatments are unsuccessful, the guidelines suggest other approaches to treatment involving specialist medical practitioners, including either slow-release oral morphine (SROM) or injectable opioid agonist therapy (iOAT). The authors of this case report, including the BCCSU’s Drs. Rupinder Brar, Christy Sutherland, and Seonaid Nolan, offer guidance on how to help patients transition from iOAT to oral OAT using a microdosing approach. Microdosing is the use of small doses of medication that are incrementally increased over time. Currently, knowledge of best practice in this area is sparse.
In this case report, a middle-aged patient with OUD and experiencing homelessness was initiated on iOAT. He had tried oral options several times in the past, but they were unsuccessful in reducing his illicit opioid use. His initial treatment was hydromorphone (injected twice per day) and SROM before bedtime. The patient gradually shifted to oral treatment (buprenorophine/naloxone) using a microdosing approach, and was simultaneously tapered off SROM and iOAT. Overall, the transition from iOAT to oral treatment was successful for this patient, despite him experiencing some intermittent withdrawal symptoms. This kind of a microdosing induction approach to buprenorphine/naloxone from iOAT may be effective in reducing or minimizing other patients’ experience of withdrawal. According to the authors, further research is needed to identify an induction protocol using microdosing, and to characterize patients who would most benefit from this strategy. This knowledge would help care providers in offering an alternative treatment strategy to patients as they combat North America’s growing opioid epidemic.