Efficacy and safety of duloxetine 60 mg once daily in the treatment of pain in patients with major depressive disorder and at least moderate pain of unknown etiology: a randomized controlled trial

Abstract

Objective: Experience of pain in major depressive disorder (MDD) can complicate diagnosis and impair treatment outcomes. This study evaluated the efficacy and safety of duloxetine in the treatment of patients with moderate pain associated with depression.

Method: In this double-blind, placebo-controlled, 8-week study, conducted from May 2005 to May 2006, outpatients 18 years of age or older, presenting with major depressive disorder (DSM-IV criteria; Montgomery-Asberg Depression Rating Scale [MADRS] score >or= 20), moderate pain (Brief Pain Inventory-Short Form [BPI-SF] average pain score >or= 3), and Clinical Global Impressions-Severity of Illness scale (CGI-S) score >or= 4 were randomly assigned to either placebo (N = 165) or duloxetine 60 mg (N = 162) once daily. Primary outcome was change in item 5 score (average pain in the last 24 hours) of the BPI-SF from baseline. Secondary measures were MADRS total score, other BPI-SF items, CGI-S, CGI-Improvement scale, Patient Global Impressions-Improvement scale, Symptom Checklist-90-Revised, response and remission rates, safety, and tolerability.

Results: Duloxetine, compared with placebo, significantly reduced pain and improved depression with significant mean changes at endpoint in both BPI-SF average pain scores (-2.57 vs. -1.64, p < .001) and in MADRS total scores (-16.69 vs. -11.31, p < .001). Remission of MDD and response rates in pain and MDD were significantly (p <or= .001) higher in duloxetine-treated patients. Duloxetine separated from placebo on most secondary outcome measures including the BPI-SF interference with daily life due to pain. Treatment-emergent adverse events (>or= 10%) in duloxetine-treated patients were nausea, hyperhidrosis, and dry mouth.

Conclusion: These results support duloxetine's efficacy and tolerability in the treatment of pain and depression in patients with at least moderate pain associated with depression.

Trial registration: ClinicalTrials.gov identifier NCT00191919 (http://www.clinicaltrials.gov).