29 y/o M was complaining of the headache and collapsed all of a sudden. EMS was known as and resuscitation was unsuccessful. It's noteworthy that U-47700 shows a reduce binding affinity than morphine in both rat and mouse MOR isoforms, yet U-47700 provides a much bigger analgesic potency than morphine https://prosyntheticchems.com/product/u-48800/