"Sexual Functioning in Long-Term Treatment of MDD: Duloxetine, Escitalopram, and Placebo: Presented at APA"
By Danny Kucharsky
TORONTO, CANADA -- May 23, 2006 -- Short-term treatment with escitalopram demonstrates worsening of sexual functioning in patients with major depressive disorder (MDD) as compared with placebo, while duloxetine is not significantly different from placebo, researchers reported here at the American Psychiatric Association Annual Meeting (APA).
The study, which lasted 8 months, was presented on May 22[nd by lead investigator Anita Clayton, MD, medical director, University of Virginia Center for Psychiatric Clinical Research, University of Virginia Health System, Charlottesville, Virginia.
Sexual dysfunction among patients with depression has a reported incidence as high as 47%, and is also a common side effect associated with antidepressant medications, affecting up to 73% of depressed patients treated with selective serotonin reuptake inhibitors, Dr. Clayton said.
The double-blind, randomized, placebo-controlled study had 2 phases. It started with an 8-week acute phase, fixed-dose comparison of duloxetine 60 mg/day in 273 patients, escitalopram 10 or 20 mg/day with 274 patients and 137 placebo patients. A 6-month flexible-dose extension phase followed.
Dose escalations and placebo rescue occurred based on predefined blinded criteria. The duloxetine dose could be increased from 60 to 90 to 120 mg/day and escitalopram from 10 to 20 mg/day.
Dr. Clayton noted the number of patients in the placebo arm significantly decreased after 8 weeks (n = 100, 73%), declining to 39 (28.5%) at week 16, and that by 8 months, only 15 placebo-treated patients (10.9%) contributed data, compared with 105 on duloxetine (38.5%) and 124 on escitalopram (45.3%).
The reason for the severe drop-out rate in the placebo group, Dr. Clayton said, is that these patients got very depressed with time. "It's very hard to keep these patients on placebo for 32 weeks," she said.
Dr. Clayton therefore cautioned that the power to detect a difference between the active treatments and placebo after 8 weeks was significantly decreased.
However, the study found a statistically significant worsening of sexual functioning as measured by the Changes in Sexual Functioning Questionnaire (CSFQ) for escitalopram versus placebo at 4 weeks (P </=.01) while duloxetine was not statistically different from placebo. The CSFQ showed a statistically significant difference for duloxetine versus escitalopram at 12 and 20 weeks (P </=.05).
There was also an advantage for duloxetine over escitalopram in satisfaction with sexual drive, interest and/or performance (P =.013 by main effect of treatment) on the Quality of Life Enjoyment and Satisfaction Questionnaire-SF.
Anorgasmia was the only treatment emergent sexual side effect reported statistically more frequently for duloxetine or escitalopram versus placebo during the course of the study (4.8%, 4.0%, and 0% for duloxetine, escitalopram, and placebo respectively; P <.05 for both active drugs versus placebo).
The study also found that at 8 weeks, categorical changes in sexual function (same, better or worse) on the CSFQ differed significantly for duloxetine versus escitalopram (P =.019) in male patients, with no significant differences in females. At 8 months, there were no statistically significant differences for both active drugs in categorical changes in CSFQ for male or female patients.
The discontinuation rate for sexual side effects did not differ for duloxetine (n = 2) versus escitalopram (n = 7, P =.07).
The study was sponsored by Eli Lilly and Company, Indianapolis, Indiana.
[Presentation title: Sexual Functioning in Long-Term Treatment of MDD: Duloxetine, Escitalopram, and Placebo. Abstract NR 199]
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