Effect of Intravenous Lidocaine on Manifestations of Fibromyalgia

BACKGROUND AND OBJECTIVES: The objective of our study was to evaluate the effect of intravenous lidocaine on the manifestations of fibromyalgia. METHODS: A randomized, double-blind, comparative study was conducted on 30 patients. All patients received 25 mg amitriptyline. Group 1 (n = 15) received 125 mL of saline; group 2 (n = 15) received 240 mg lidocaine in 125 mL of saline once a week for 4 weeks. The following parameters were evaluated: clinical manifestations before and 4 weeks after treatment; pain intensity on a numerical scale. RESULTS: All patients were female, and the mean age was 44.7 +/- 10.5 years in group 1 and 40.9 +/- 11.6 years in group 2. No difference in pain intensity or the number of tender points was observed between groups at any time point. Both groups demonstrated a significant decrease in the two parameters after treatment. A significant reduction in sleep disorders, paresthesia, and headache was observed after treatment in the two groups, but there was no significant difference between groups. There was no significant reduction in fatigue, subjective edema or morning stiffness after treatment in either group, without a significant difference between groups. CONCLUSIONS: The addition of 240 mg intravenous lidocaine (once a week) to 25 mg amitriptyline for 4 weeks did not modify pain intensity or manifestations in patients with fibromyalgia compared with amitriptyline alone.