OPRM1 and respiratory depression: As a partial μ-opioid receptor (MOR) agonist, buprenorphine is associated with less respiratory depression, fatal overdose, and overall mortality12,13,14,15,16,17 as well as fewer adverse effects than full MOR agonists (ie, morphine sulfate or oxycodone hydrochloride).18,19,20,21,22 Drug clearance does not change with age, renal impairment, or mild hepatic impairment.23,24,25 These properties make buprenorphine an attractive replacement for other opioids.