# Cannabinoid Effects of Metamizol/Dipyrone: A Possible Second Life in Pediatric Anesthesia for a Vintage Drug

## TL;DR

Metamizol is an effective and safe painkiller for children after surgery, possibly due to effects on the endocannabinoid system.

## Contribution

The paper highlights metamizol's potential as a postoperative analgesic in pediatrics and its possible endocannabinoid system modulation.

## Key findings

- Metamizol provides effective postoperative analgesia comparable to other NSAIDs and paracetamol.
- Short-term use of metamizol is well tolerated with low serious adverse events in pediatric patients.
- Metamizol's analgesic effects involve cyclo-oxygenase inhibition and modulation of opioid and endocannabinoid systems.

## Abstract

Background: Metamizol (dipyrone) is a widely used analgesic and antipyretic drug in several European countries, particularly for postoperative pain management in both adult and pediatric populations. Methods: A narrative literature review was conducted to evaluate the efficacy, safety, and pharmacological mechanisms of metamizol in postoperative pain management. A comprehensive search of PubMed, Scopus, and the Cochrane Library was performed, and included articles published up to 2024. Search terms included metamizol, dipyrone and children. Results: The available evidence indicates that metamizol provides effective postoperative analgesia, with an efficacy comparable to that of other non-steroidal anti-inflammatory drugs and paracetamol. Pediatric studies similarly support its effectiveness in postoperative settings. Regarding safety, short-term use of metamizol appears to be well tolerated, with a low incidence of serious adverse events. Mechanistic studies suggest that metamizol exerts analgesic effects through a multimodal pathway, involving not only cyclo-oxygenase inhibition but also modulation of opioid and endocannabinoid systems. Conclusions: Metamizol represents an effective and generally well-tolerated option for short-term postoperative pain management in both adults and children when used under appropriate clinical monitoring. Current evidence supports a favorable benefit-to-risk balance for short-term use while highlighting the need for caution during prolonged therapy. Further large-scale, prospective studies are warranted to better define rare adverse events, clarify interindividual risk factors, and refine the understanding of their non-classical mechanisms of action.