This pilot study will evaluate the feasibility and clinical utility of extended-release injectable buprenorphine (XR-BUP) for the treatment of opioid use disorder (OUD) among individuals at high-risk for overdose (OD).

FASTER-BUP is a 24-week observational pilot study evaluating the feasibility and clinical utility of XR-BUP (brand name: Sublocade) for the treatment of OUD among individuals at high-risk of OD. Forty participants with moderate to severe OUD starting treatment with XR-BUP as part of standard of care will be followed.

Inclusion Criteria:

Participants must meet ALL the following criteria to be eligible to participate for the study:

1. Be above 19 years of age;
2. Be diagnosed with moderate or severe OUD as evidenced by their approval for treatment with XR-BUP (Sublocade);
3. Be at high-risk for recurrent overdose, defined as having experienced a recent non-fatal overdose within the past 6 months (e.g., admission to the emergency department for an overdose OR self-reported OD that required Naloxone administration OR had an overdose where an ambulance arrived at the scene);
4. Have a new prescription for XR-BUP, but have not yet initiated treatment;
5. Be able and willing to follow study procedures;
6. Be able to provide adequate locator information (e.g., phone number and at least one emergency contact);
7. Be able and willing to provide written informed consent;
8. Be able to understand, communicate and speak with the research staff. Non-English speaking individuals will require a translator to be present during all study visits and during all study activities. The translator will be independent (e.g., not known to the participant to prevent the risk for coercion or misrepresentation).

Exclusion Criteria:

Participants will be excluded from the study if ANY of the following criteria are met:

1. Be on OAT other than buprenorphine/naloxone in the 7 days prior to screening;
2. Be on a stable buprenorphine/naloxone dose for more than 27 days prior to screening;
3. Use of an investigational drug in the 30 days prior to screening;
4. Incarcerated, pending legal action or other reasons that might prevent completion of the study.

Approximately 40 eligible participants are planned to be enrolled into the study. Interested individuals must meet all of the inclusion criteria and none of the exclusion criteria to be eligible for the study.