To evaluate the feasibility of a randomized-controlled trial and to obtain estimates of the effects of combined cognitive-behavioral therapy (CBT) and milnacipran for the treatment of fibromyalgia.
Fifty-eight patients with fibromyalgia were randomized to 1 of the 3 treatment arms: (1) combination therapy (n = 20); (2) milnacipran+education (n = 19); and (3) placebo+CBT (n = 19). Patients received either milnacipran (100 mg/d) or placebo. Patients also received 8 sessions of phone-delivered CBT or educational instructions, but only from baseline to week 9. Assessments were conducted at baseline, week 9, and 21. The primary endpoints were baseline to week 21 changes in weekly average pain intensity and physical function (SF-36 physical function scale).
Compared with milnacipran, combination therapy demonstrated a moderate effect on improving SF-36 physical function (SE = 9.42 [5.48], P = 0.09, effect size = 0.60) and in reducing weekly average pain intensity (mean difference [SE] = -1.18 [0.62], P = 0.07, effect size = 0.67). Compared with milnacipran, CBT had a moderate to large effect in improving SF-36 physical function (mean difference [SE] = 11.0 [5.66], P = 0.06, effect size = 0.70). Despite the presence of concomitant centrally acting therapies, dropout rate was lower than anticipated (15% at week 21). Importantly, at least 6 out of the 8 phone-based therapy sessions were successfully completed by 89% of the patients; and adherence to the treatment protocols was > 95%.
In this pilot study, a therapeutic approach that combines phone-based CBT and milnacipran was feasible and acceptable. Moreover, the preliminary data supports conducting a fully powered randomized-controlled trial.