Data from two 9- to 10-week double-blind, placebo-controlled, randomized clinical trials of
duloxetine (60 to 120 mg) in DSM-IV-defined GAD were analyzed (study 1 was conducted from July 2004 to September 2005; study 2 was conducted from August 2004 to June 2005). Efficacy was assessed with the Hamilton Rating Scale for Anxiety (HAM-A), visual analog scales (VAS) for
pain, the Hospital Anxiety Depression Scale (
HADS), the Clinical Global Impressions-Improvement of Illness (CGI-I) scale, the Patient Global Impressions-Improvement (PGI-I) scale, and the Sheehan Disability Scale (SDS) global functional impairment scale.
RESULTS: Of 840 patients randomly assigned to treatment, 61.3% (302
duloxetine, 213 placebo) had VAS scores ≥ 30 mm on at least 1 of the
pain scales, indicating clinically significant
pain. Among those patients with concurrent
pain at baseline, change from baseline to endpoint in the HAM-A total score (42.9% change in mean scores for
duloxetine, 31.4% for placebo),
HADS anxiety scale (40.3% vs. 22.8%),
HADS depression scale (36.1% vs. 20.5%), HAM-A psychic factor (45.9% vs. 29.9%), and SDS global functional improvement score (45.5% vs. 22.1%) was significantly (all p's < .001) greater for
duloxetine compared with placebo. Improvement on the CGI-I (p = .003) and PGI-I (p < .001) was also significantly greater for
duloxetine. Response (HAM-A total score decrease ≥ 50%) (49% vs. 29%) and remission (HAM-A total score ≤ 7 at endpoint) (29% vs. 18%) rates were significantly greater for
duloxetine compared with placebo (p < .001 and p = .041, respectively).
Duloxetine demonstrated statistically significantly greater reduction in
pain on all 6 VAS
pain scales (all p's < .001 except
headaches with p < .002) (for
duloxetine, percent change in means from baseline to endpoint ranged from 40.1% to 45.2% across the 6 VAS scales; for placebo, 22.0% to 26.3%).
CONCLUSION:
Duloxetine, relative to placebo, improves anxiety symptoms,
pain, and functional impairment among patients with GAD with concurrent clinically significant
pain.
TRIAL REGISTRATION: clinicaltrials.gov Identifiers: NCT00122824 (study 1) and NCT00475969 (study 2).