Text adapted in 2023 from "Opioid Use and Opioid Use Disorders" in The Primary Care Addiction Toolkit. Available online only.
Prescribing iOAT
Clinical guidelines recommend injectable opioid agonist treatment (iOAT) with hydromorphone or diacetylmorphine (pharmaceutical-grade heroin) for people with severe, treatment-refractory opioid use disorder who continue to inject opioids (Canadian Research Initiative in Substance Misuse, 2019; Centre for Addiction and Mental Health, 2021).
There are two pharmacological agents for iOAT in Canada. Injectable hydromorphone has been approved for the treatment of opioid use disorder, but injectable diacetylmorphine is considered off-label use for this indication and can only be accessed through Health Canada’s Special Access Programme. iOAT is administered in a dedicated clinic and remains limited to clinicians with specific expertise in this treatment.
How iOAT works
iOAT is administered under strictly monitored, medically supervised conditions (Fairbairn et al., 2019). It involves visiting a supervised injection site up to three times per day. Patients self-inject a prescribed injectable opioid under supervision of a health care professional. The injection can be done intramuscularly, intravenously or subcutaneously.
A post-intake assessment is performed to assess for dose tolerance and safety concerns. Patients on iOAT may also receive a co-prescription for OAT such as slow-release oral morphine or methadone to prevent withdrawal and cravings between iOAT doses. iOAT is considered an open-ended treatment with the possibility of transitioning to oral opioid agonist therapy.
Candidates for iOAT
Injectable OAT is indicated for patients with severe opioid use disorder who have not benefitted from oral OAT and who continue with illicit injection opioid use.
