The Impact of Intramuscular Depot Betamethasone Injection (Diprospan) on Patients with Fibromyalgia and Normal C-Reactive Protein Levels

Introduction: Intramuscular depot betamethasone treatment had resulted in a significant improvement among fibromyalgia patients with elevated C-reactive protein (C-RP) levels. Here, we wanted to evaluate the same regimen of treatment among fibromyalgia patients with normal C-RP levels. These patients represent the overwhelming majority of fibromyalgia patients. Patients and Methods: Consecutive patients with fibromyalgia attending the outpatient rheumatology clinic, with normal C-RP level and negative serology, who had failed different medical treatment, were asked to participate in our study. All patients have qualified the American College of Rheumatology (ACR) criteria from 2010. After consent, patients had an intra-muscular injection of 14 mg depot betamethasone at the gluteal area. Just prior to the injection, 1 week and 1 month later, patients were interviewed by phone and asked to answer the Fibromyalgia Revised Questionnaire (FIQR). Wilcoxon’s signed ranked test was used to compare the results 1 week and 1 month following the injection, compared to the base line scores. Results: Seventeen (17) patients completed the study. Favorable effects were seen regarding 13 out of 19 parameters one week following the injection, including functional parameters, mood and anxiety, tenderness to touch and intolerance to noise and light. No significant favorable effect was seen 1 month following the injection except for one parameter: ability of walking for twenty minutes. Conclusions: IM depot betamethasone injection had very limited and transient favorable effects on fibromyalgia patients with normal C-RP levels. Such a treatment is not a recommended modality of routine treatment, among fibromyalgia patients with normal C-RP levels.