Open AccessComparison of Amitriptyline, Cyclobenzaprine, and Placebo in the Treatment of Fibromyalgia
Author(s) -
Carette Simon,
Bell Mary J.,
Reynolds W. John,
Haraoui Boulos,
Mccain Glenn A.,
Bykerk Vivian P.,
Edworthy Steven M.,
Baron Murray,
Koehler Barry E.,
Fam Adel G.,
Bellamy Nicholas,
Guimont Chantal
Publication year - 1994
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780370106
Subject(s) - amitriptyline , placebo , fibromyalgia , tolerability , medicine , anesthesia , adverse effect , alternative medicine , pathology
Objective . To compare the relative efficacy and tolerability of amitriptyline, cyclobenzaprine, and placebo in the treatment of fibromyalgia, and to identify predictors of response to amitriptyline and cyclobenzaprine. Methods , Two hundred eight patients who fulfilled the American College of Rheumatology criteria for the classification of fibromyalgia were entered into a 6‐month prospective, double‐blind, multicenter trial and were randomized to 1 of 3 treatment groups: amitriptyline, cyclobenzaprine, or placebo. Results . After 1 month, 21%, 12%, and 0% of the amitriptyline, cyclobenzaprine, and placebo patients, respectively, had significant clinical improvement (amitriptyline versus placebo P = 0.002, cyclobenzaprine versus placebo P = 0.02, amitriptyline versus cyclobenzaprine P not significant). These percentages increased to 36%, 33%, and 19%, respectively, at the 6‐month assessment ( P not significant). The nature and frequency of side effects reported by patients treated with amitriptyline and those reported by patients treated with cyclobenzaprine were similar. A normal Minnesota Multiphasic Personality Inventory (MMPI) profile at baseline was predictive of clinical improvement at the 1‐month evaluation (odds ratio 3.3, 95% confidence interval 1.2—9.0). However, neither the MMPI profile nor any of the demographic, clinical, or functional parameters evaluated at baseline predicted long‐term response. Conclusion . Our data confirm the short‐term efficacy of amitriptyline and cyclobenzaprine in a small percentage of patients with fibromyalgia. Long‐term efficacy could not be demonstrated because of a higher‐than‐expected placebo response. Predictors of response to these drugs could not be determined.