Opioid Drug Interaction Study

Inclusion Criteria: * English-speaking and literate participants, able to understand and sign Informed Consent Document * ages 18 to 55 years old inclusive * BMI of greater than/equal to 17 and approximately less than or equal to 30 * self-reported opioid use * self-reported sedative-like drug use * women of childbearing potential must not be pregnant or breastfeeding at screening and be using an effective form of contraception throughout study participation * otherwise healthy as determined by the medical/research team based on medical history, physical examination, vital signs, laboratory chemistries (blood chemistry with liver function tests and hematology, urinalysis and microscopic evaluation, 12-lead electrocardiogram) * willing and able to comply with all testing requirements defined in the protocol * adequate venous access (determined by RN) for pharmacokinetic blood draws Exclusion Criteria: * physical dependence on alcohol, opioids, benzodiazepines or sedative/hypnotics requiring medical management/detoxification * seeking treatment for opioid or any other drug use * acute medical problem (e.g., infection) or chronic medical problem requiring daily medication or ongoing medical care (e.g., hypertension, cardiovascular disease, diabetes, respiratory disorders \[e.g., asthma, COPD\]) * clinically significant abnormal ECG (as determined by study physician/cardiologist) * clinically significant abnormal laboratory findings (e.g., liver function tests greater than 3x the upper limits of normal range) * current or past history of major psychiatric disorder that would limit ability to participate in the study (e.g., bipolar disorder). * recent use of CYP2C9, CYP2D6 and CYP3A4 inhibitor or inducer that is long-acting and not amenable to a wash-out period after enrollment * known hypersensitivity to any of the study drugs * currently pregnant or breastfeeding * currently under parole or probation with urine testing requirements