pISSN 2005-9159
eISSN 2093-0569

Experimental Research Article

Korean J Pain 2023; 36(4): 425-440

Published online October 1, 2023 https://doi.org/10.3344/kjp.23161

Copyright © The Korean Pain Society.

Muscimol as a treatment for nerve injury-related neuropathic pain: a systematic review and meta-analysis of preclinical studies

Hamzah Adel Ramawad1 , Parsa Paridari2 , Sajjad Jabermoradi2 , Pantea Gharin2 , Amirmohammad Toloui2 , Saeed Safari3 , Mahmoud Yousefifard2

1Department of Emergency Medicine, NYC Health + Hospitals, Coney Island, NY, USA
2Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
3Men's Health and Reproductive Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Correspondence to:Mahmoud Yousefifard
Physiology Research Center, Iran University of Medical Sciences, Hemmat Highway, Tehran 14496-14535, Iran
Tel: +98(21)86704771, Fax: +98(21)86704771, E-mail: yousefifard20@gmail.com

Saeed Safari
Men's Health and Reproductive Health Research Center, Shohadaye Tajrish Hospital, Tajrish Square, Shahid Beheshti University of Medical Sciences, Tehran 1989934148, Iran
Tel: +98(21)86704771, Fax: +98(21)86704771, E-mail: safari266@gmail.com

Handling Editor: Hyun Kang

Received: June 2, 2023; Revised: July 27, 2023; Accepted: August 1, 2023

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background: Muscimol’s quick onset and GABAergic properties make it a promising candidate for the treatment of pain. This systematic review and meta-analysis of preclinical studies aimed at summarizing the evidence regarding the efficacy of muscimol administration in the amelioration of nerve injury-related neuropathic pain.
Methods: Two independent researchers performed the screening process in Medline, Embase, Scopus and Web of Science extracting data were extracted into a checklist designed according to the PRISMA guideline. A standardized mean difference (SMD [95% confidence interval]) was calculated for each. To assess the heterogeneity between studies, I2 and chi-square tests were utilized. In the case of heterogeneity, meta-regression and subgroup analyses were performed to identify the potential source.
Results: Twenty-two articles met the inclusion criteria. Pooled data analysis showed that the administration of muscimol during the peak effect causes a significant reduction in mechanical allodynia (SMD = 1.78 [1.45–2.11]; P < 0.0001; I2 = 72.70%), mechanical hyperalgesia (SMD = 1.62 [1.28–1.96]; P < 0.0001; I2 = 40.66%), and thermal hyperalgesia (SMD = 2.59 [1.79–3.39]; P < 0.0001; I2 = 80.33%). This significant amendment of pain was observed at a declining rate from 15 minutes to at least 180 minutes post-treatment in mechanical allodynia and mechanical hyperalgesia, and up to 30 minutes in thermal hyperalgesia (P < 0 .0001).
Conclusions: Muscimol is effective in the amelioration of mechanical allodynia, mechanical hyperalgesia, and thermal hyperalgesia, exerting its analgesic effects 15 minutes after administration for up to at least 3 hours.

Keywords: Analgesia, Gamma-Aminobutyric Acid, Hyperalgesia, Meta-Analysis, Muscimol, Neuralgia, Pain, Peripheral Nerve Injuries, Spinal Cord Injuries.