Effects of milnacipran on neurocognition, pain, and fatigue in fibromyalgia: a 13-week, randomized, placebo-controlled, crossover trial.

OBJECTIVE

To investigate whether milnacipran is safe and effective in improving cognitive function in patients with fibromyalgia.

METHOD: Patients were randomly assigned to receive milnacipran or placebo for 6 weeks, followed by a 1-week washout and then crossover to the other arm for another 6 weeks. The overall trial lasted 13 weeks and was conducted between July 2011 and May 2013. Assessments were performed at each visit. Neurocognition was measured by the Brief Assessment of Cognition (BAC) and MATRICS. Pain was assessed by the visual analog scale (VAS) for pain. Global assessment of fibromyalgia symptoms was measured by the Fibromyalgia Impact Questionnaire (FIQ) and tender point examination. Depression was assessed by the Beck Depression Inventory (BDI). Fatigue was assessed by the Fatigue Severity Scale. Functional outcome was evaluated by the Health Assessment Questionnaire. The Clinical Global Impressions-Severity of Illness (CGI-S) and Improvement (CGI-I) scales and the Patients Clinical Global Impression of Change were used to measure the global impression of severity and improvement.

RESULTS

26 subjects were screened, and 20 subjects completed the trial. The change in verbal memory (P = .001) and the composite T score (P = .044) of the BAC and the change in the attention-vigilance domain T score (P = .042) were significantly improved, but there were no differences between the drug and placebo groups. The changes in the CGI-S scores were not significant, but the changes in the Clinical Impression-Improvement (CGI-I) scores showed worsening in the placebo group at week 1 (P = .032), week 2 (P = .024), week 4 (P = .024), and week 6 (P = .60) compared to baseline. The change in FIQ scores was not significant.

CONCLUSIONS

Milnacipran may have a potential role in the improvement of pain, disability, and mood. The effect of milnacipran on cognition in fibromyalgia needs further research.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01829243.