Effectiveness of dipyrone (metamizole) in postoperative analgesia: A systematic review and meta-analysis

Abstract

Background

Postoperative pain requires effective management. This study reviews the effectiveness and safety of dipyrone/metamizole for postoperative pain management in adults and children.

Materials and methods

The online databases Medline, OVID, Embase, and LILACS were searched in November 2024 for randomized controlled trials comparing dipyrone/metamizole with other drugs or placebo in postoperative settings. Outcomes included immediate postoperative pain scores and opioid consumption (Oral Morphine Equivalence, OME) in the first 24 h.

Results

Thirty studies were included. In adult patients, no significant OME differences were found between dipyrone and NSAIDs (2.1 mg; 95%CI -3.4 to 7.7), paracetamol (−1.3 mg; 95%CI -5.9 to 3.3), or placebo (−2.7 mg; 95%CI -9.2 to 3.8). In the ICU study, dipyrone showed lower OME than paracetamol (−9.9 mg; 95%CI -18.2 to −1.6). In pediatric studies, there were no differences in OME between dipyrone and paracetamol (0 mg; 95%CI -0.1 to 0.1) or placebo (−0.1 mg; 95%CI -0.3 to 0.2). No significant side effects were reported.

Conclusion

Dipyrone is as effective as other non-opioid analgesics commonly used for postoperative analgesia, and more effective than paracetamol in ICU patients. The reviewed studies indicate that its use is safe, and therefore it should be considered as an option for multimodal analgesia in pain management guidelines.