The effect of intravenous lidocaine infusion on manifestations of fibromyalgia manifestations were recorded before and 4 weeks after treatment. Pain intensity was rated on a numerical scale.The combination of 240 mg intravenous lidocaine (once a week) and 25 mg amitriptyline for 4 weeks did not modify pain intensity or manifestations in patients with fibromyalgia.

Thirty patients ranging in age from 18 to 60 years, with fibromyalgia (American College of Rheumatology criteria: pain in the four quadrants of the body for at least 3 months and a minimum of 11 out of 18 tender points) were studied. Other manifestations were also recorded: sleep disorders, fatigue, subjective edema, depression, and paresthesia.

Criteria for exclusion were alterations in thyroid, rheumatological, renal and hepatic function; trauma; rheumatic, neuromuscular or psychiatric disease; infectious arthropathy; other pain syndromes; drug hypersensitivity, and pregnancy.

All patients received amitriptyline at a dose of 12.5 mg in the first week and 25 mg over the subsequent 4 weeks. Patients of group 1 (n = 15) received 125 mL 0.9% saline and patients of group 2 (n = 15) received 240 mg lidocaine diluted in 125 mL 0.9% saline. The solutions were infused over a period of 1 h, once a week, for 4 weeks (T1, T2, T3 and T4).

Inclusion Criteria:

• 18 to 60 years, with fibromyalgia (American College of Rheumatology criteria: pain in the four quadrants of the body for at least 3 months and a minimum of 11 out of 18 tender points

Exclusion Criteria:

• Thyroid, rheumatological, renal and hepatic function
• Trauma
• Rheumatic, neuromuscular or psychiatric disease
• Infectious arthropathy
• Other pain syndromes
• Drug hypersensitivity; AND
• Pregnancy