Duloxetine 60 mg once daily dosing versus placebo in the acute treatment of major depression

Existing therapies for major depressive disorder (MDD) have either limited efficacy and/or poor tolerability. The present study examined the effects of duloxetine, a potent and balanced dual reuptake inhibitor of serotonin (5-HT) and norepinephrine (NE), in patients with MDD. Adult patients (N=267) with MDD were randomly assigned to receive duloxetine (60 mg/day) or placebo in this 9-week, multi-center, double-blind, parallel-group clinical trial. Efficacy was evaluated using the 17-item Hamilton Depression Rating Scale (HAMD₁₇), Visual Analog Scales (VAS) for pain, Clinical Global Impression of Severity (CGI-S), Patient's Global Impression of Improvement (PGI-I), and Quality of Life in Depression Scale (QLDS). Safety was evaluated by assessing discontinuation rates, adverse event rates, vital signs, and laboratory tests. Duloxetine (60 mg QD) significantly reduced the HAMD₁₇ total score compared with placebo at the end of 9-week therapy. Estimated probabilities of response and remission were 65 and 43%, respectively, for duloxetine compared with 42 and 28% for placebo. Duloxetine also reduced overall pain, back pain, shoulder pain and time in pain while awake significantly more than placebo. Global measures of improvement, including PGI-I and QLDS, were significantly improved by duloxetine compared with placebo. Discontinuations due to adverse events were more frequent for duloxetine-treated patients (12.5%) than for placebo-treated patients (4.3%). Nausea, dry mouth, dizziness, and constipation were more frequent for duloxetine than placebo. There was no significant incidence of hypertension, nor any other safety issues. Duloxetine 60 mg administered once daily appears to be a safe and effective treatment for MDD.