Evaluation of the Safety and Effects of Psychoactive Substances in People With Past Opioid Use

Inclusion Criteria

• •1. English-speaking, 18- to 55-year-old males or females.
• •2. Female subjects must have a negative serum pregnancy test at time of screening and negative urine pregnancy test upon admission. In addition, female subjects must meet one of the following conditions:
• •* Is a woman of non-childbearing potential defined as no menses for at least 12 months with status confirmed by FSH and estradiol levels at screening or surgically sterile at screening visit OR
• •* Is a woman of childbearing potential and using a contraceptive method that is highly effective, with a failure rate of \<1%, from Screening until 9 months after receiving the study medication. The investigator should evaluate the potential for contraceptive method failure (e.g., noncompliance, recently initiated) in relationship to the dose of study intervention.
• •3. Male subjects must agree to the following from Day 1 until 9 months after receiving the study medication:
• •• Not donate fresh unwashed semen
• •Plus, either:
• •* Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent OR
• •* Use a male condom and should also be advised of the benefit for a female partner to use a highly effective method of contraception as a condom may break or leak when having sexual intercourse with a woman of childbearing potential who is not currently pregnant.
• •* Use a male condom when engaging in any activity that allows for passage of ejaculate to another person
• •4. Physically healthy, as determined by a clinical interview with a physician, laboratory tests (urinalysis, blood chemistry, 12-lead ECG), physical examination, and self-reported medical history.
• •5. No current or past diagnosis of severe mental illness, as determined by a clinical interview.
• •6. Clinical laboratory test results (CMP, CBC, etc.) must be within the normal reference range or with acceptable deviations that are judged to be not clinically significant by a study physician.
• •7. Have a history of self-reported recreational opioid use as defined by at least 10 times in the past year and at least once in the 12 weeks before screening.
• •8. Able and willing to give signed informed consent, reliable, and willing to make themselves available for the study's duration and follow study procedures.
• •9. Agree not to consume any recreational drugs during the study (THC is excluded).
• •10. Able to perform study procedures as determined by clinical judgment.
• •11. Able to meet eligibility requirements of the Qualification Phase (i.e., drug discrimination) and Naloxone Challenges.