Effectiveness of morphine in controlling acute pain in the emergency department

Acute pain is one of the leading complaints in emergency departments (EDs), it contributes to patient distress and emergency service burden. Prompt and effective pain relief is an essential component of emergency care. From pharmacologic options, intravenous (IV) morphine was considered a gold standard for treating moderate to severe acute pain in the ED due to its rapid onset, titrability, and strong analgesic properties. This systematic review aimed to evaluate the effectiveness of IV morphine for the management of acute pain in ED settings. A literature search was conducted in electronic databases to identify studies published between the years 2015 and 2025. Eight studies with a total of 2,156 adult patients were included: six randomized controlled trials and two observational studies. The included studies compared IV morphine to fentanyl, ketamine, meperidine, and acetaminophen, or examined alternative administration strategies. The findings showed that IV morphine was effective in reducing moderate to severe acute pain across various clinical contexts. In several studies, morphine showed comparable analgesic efficacy to fentanyl and ketamine, but fentanyl provided a more rapid onset in some cases. Patient-controlled analgesia using morphine improved patient satisfaction but showed limited additional benefit in pain score reduction compared to standard titration methods. The combination of morphine with acetaminophen did not produce significant improvements over morphine alone. Morphine was well tolerated, with common side effects including nausea and sedation. Hence, IV morphine is a good option for acute pain control in the ED, with comparable alternatives available depending on clinical needs.