Intravenous lidocaine for fibromyalgia syndrome: an open trial.

Fibromyalgia is a disorder characterized by chronic widespread pain. In this study, we investigated the effect of intravenous infusions of lidocaine in pain and quality of life of patients with fibromyalgia. Twenty-three consecutive patients were included in the study, which consisted on five sequential intravenous 2% lidocaine infusions with rising dosages (2-5 mg/kg, days 1-5). Fibromyalgia Impact Questionnaire (FIQ), Health Assessment Questionnaire, and a visual analog scale (VAS) for pain were applied before the first lidocaine infusion, immediately after the fifth infusion and 30 days after the fifth infusion. A significant improvement was observed in the FIQ scores after the fifth infusion (73.52 +/- 16.56 vs 63.29 +/- 21.21, p = 0.02), which was maintained after 30 days (73.52 +/- 16.56 vs 63.85 +/- 24.59, p = 0.04). Similar results were seen concerning the VAS: 8.19 +/- 1.76 vs 6.84 +/- 2.44, p = 0.01 and 8.19 +/- 1.76 vs 7.17 +/- 2.35, p = 0.05, respectively. Intravenous lidocaine infusions are safe and effective in the management of fibromyalgia.