A Randomized Placebo-Controlled Trial of Sustained-Release Amitriptyline in Primary Fibromyalgia

Objectives: The objective of this study was to evaluate the efficacy and safety of a sustained-release preparation of amitriptyline, taken once daily, in patients with primary fibromyalgia [FS]. Methods: Forty-six patients were evaluated at one and two months in a double-blind placebo-controlled study. The primary evaluation of the outcome of therapy was based on the comparison of the "clinically meaningful response rate in the two treatment groups. Results: At four weeks, five of the 24 patients receiving amitriptyline [A] [21%, 95% CI 7.1%-42.4%] and none of the 22 patients receiving placebo [P] [95% CI 0-15.4%] were responders [P = 0.050]; at eight weeks there were 14 P58%, 95% CI 36.6-77.9%] responders in group A and none in group P [(%% CI 0-15.4%] [P < 0.001]. Adverse events were observed in Group A only and were minor. Conclusion: Sustained-release amitriptyline may be beneficial in the treatment of some FS patients.