Comparison of the safety and efficacy of a morphine-alfentanil mixture versus morphine alone for the management of severe pain in the Emergency Department

This study is testing whether adding a fast-acting painkiller (alfentanil) to the standard slower-acting painkiller (morphine) can relieve severe pain more quickly in the emergency department. Alfentanil kicks in within minutes while morphine takes longer to work. Combining them may give patients faster relief without extra risk. Participants are randomly assigned to receive either the combination or morphine alone. You may be eligible if: - You are between 18 and 70 years old - You have severe pain (score of 7 or higher out of 10) - You weigh more than 50 kg - You can communicate clearly in English You may NOT be eligible if: - You are allergic to alfentanil, fentanyl, or morphine - You have severe heart or breathing disease - You regularly use opioids or have a history of opioid dependence - You take monoamine oxidase inhibitor (MAOI) medications - You have significant cognitive impairment - You have kidney or liver problems - You are pregnant or breastfeeding Talk to your doctor about whether this trial might be right for you.