Open Label Comparison of Injectable Buprenorphine ( Brixadi®) and Naltrexone (Vivitrol®) for Opioid Use Disorder

This project aims to elucidate the brain effects of opioid use disorder (OUD) treatments. The study will investigate the cognitive effects of extended-release preparations of a partial opioid agonist and an antagonist. To this end, the study will use up to three monthly injections of buprenorphine (XRBUP, Brixadi®) and naltrexone (XRNTX, Vivitrol®). Domain-specific brain activity will be induced by cognitive tasks and recorded with Magnetic Resonance Imaging. Participants will be imaged at baseline and in the interval between the 1st and 2nd injection and followed for up to three months.

Inclusion Criteria18-65 Years oldOUD by DSM5 Criteria, confirmed by history and physical examination including urine toxicology, medical records and self-reportOpioids are the drug of choiceInterested in either injectable extended release agonist or antagonist treatmentHave a stable address, working command of English language, and telephone access.Exclusion CriteriaLifetime diagnoses of any psychotic disorder, e.g. schizophrenia, schizoaffective disorder and bipolar affective disorder type 1.Psychiatric disorders requiring current medication treatment, e.g. moderate to severe depression, with the exception of mild to moderate Depressive and Anxiety disorders and Attention Deficit Hyperactivity Disorder that does not require prescription stimulants.Polysubstance users whose drug of choice is not an opioid.Medical contraindications for the study medications, e.g. active liver disease.Medical and surgical conditions such as malignancy that may affect patients' ability to receive XRNTX or XRBUP treatment because it may interfere with opioid analgesia.Contraindications for MRI, e.g. claustrophobia, indwelling foreign magnetic agents.Women of childbearing age who do not use an effective contraceptive.