Rheumatology Unit, Department of Medicine, University and Azienda Ospedaliera Universitaria Integrata of Verona, Italy. Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University and Azienda Ospedaliera Universitaria Integrata of Verona, Verona, Italy.
OBJECTIVE Several pharmacological treatments have been proposed for the treatment of Complex regional pain syndrome type-I (CRPS-I) in adults, but data regarding the efficacy of various agents for this disease is scarce. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to analyse pharmacological approaches in adults with CRPS-I. METHODS We systematically searched PubMed, Scopus, and Web
of Science databases from the inception date to 30, June 2021 for identifying placebo-controlled or active-controlled RCTs using bisphosphonates, ketamine, corticosteroids, anti-epileptics, NSAIDs/COXIBs, opiates, antidepressants, scavengers/magnesium sulphate or intravenous immunoglobulins for the treatment of CRPS-I. The primary outcomes included changes in the visual analogue scale (VAS) or numeric rating scale (NRS) for pain before and after treatment. RESULTS We included 20 placebo-controlled or active-controlled RCTs (for a total of 818 CRPS-I adults) that used bisphosphonates (n = 7), ketamine (n = 2), corticosteroids (n = 2), anti-epileptics (n = 1), NSAIDs/COXIBs (n = 2), scavengers/magnesium (n = 5), or intravenous immunoglobulins (n = 1) to treat CRPS-I during a median follow-up of 26 weeks. The treatment with bisphosphonates showed a significant reduction of the values of the VAS/NRS pain scale compared with placebo or reference therapy (random effects weighted mean difference [WMD]: -23.8, 95%CI-28.0 to -19.6; I2=36.4%). Treatment with ketamine also documented a reduction in the values of the VAS/NRS pain scale (random effects WMD: -8.27,95%CI -12.9 to -3.70; I2=0%). Treatment with other agents did not improve the values of the VAS/NRS pain scale. CONCLUSION This systematic review and meta-analysis supports the recommendation of parenteral bisphosphonates as the first-line agent in the treatment of CRPS-I. REGISTRATION NUMBER Open Science Framework registries; osf.io/et9gu.