Rationale Opioid-related overdose deaths involving benzodiazepines have increased in recent years, and prior studies have reported that clinically used benzodiazepines can enhance the respiratory-depressant effects of mu opioid receptor (MOR) agonists. TPA023B is an α1-sparing GABA A positive allosteric modulator developed as a potential anxiolytic with fewer benzodiazepine-typical side effects. However, it is unknown if and t...