Suvorexant as an Adjunct to Buprenorphine Induction and Maintenance in Persons Who Use Fentanyl

Inclusion Criteria:

• Aged 18-65
• Meets DSM-5 criteria for opioid use disorder (OUD) with evidence of physical dependence on opioids
• Provides a urine sample that tests positive for fentanyl and/or fentanyl analogues
• Interest in being maintained on buprenorphine for OUD
• Plans to reside in current area for study period
• Achieving a study maintenance dose of >=8mg sublingual buprenorphine/naloxone
• Willing to comply with study protocol
• Have no clinically significant chronic medical or surgical disorders or conditions that are judged by the investigators to prevent participation

Exclusion Criteria:

• Medically contraindicated for buprenorphine, extended-release (XR)-buprenorphine (Sublocade), or suvorexant (as per medication labels)

• Pregnant or breast feeding

• Severe Diagnostic and Statistical Manual (DSM)-5 alcohol or benzodiazepine use disorder or evidence of alcohol/benzodiazepine physical dependence

• Have a known allergy to the study medications

• Past 30-day prescribed use of suvorexant for the indication of insomnia

• Current benzodiazepine or other prescribed medication for the indication of insomnia

• Urine sample testing positive for benzodiazepine at screening and admission to residential treatment

• Current narcolepsy, restless leg syndrome or sleep paralysis

• High risk for current sleep apnea

• Current (past 30-day) suicidal behaviors

• Severe hepatic or renal impairment

  • aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >3x upper limit of normal (ULN)
  • Total bilirubin >2x ULN
  • Creatinine >1.5x ULN

• Past year clinically-significant psychiatric condition judged to interfere with study participation

• Lack of access to stable housing (necessary for electronic pill dispenser charging)

• Have circumstances that would interfere with study participation (e.g., impending jail)