THE USE OF VENLAFAXINE IN THE TREATMENT OF MAJOR DEPRESSION AND MAJORDEPRESSION ASSOCIATED WITH ANXIETY - A DOSE-RESPONSE STUDY

This l2-week, double-blind, placebo-controlled study evaluated the eff icacy and safety of venlafaxine as first-line therapy for the treatmen t of major depression and major depression associated with anxiety in 384 adult outpatients. Fixed total daily dosages of 75, 150, and 200 m g of venlafaxine were administered in a twice-a-day regimen. Primary e fficacy parameters were the Hamilton Rating Scale for Depression (HAM- D) total score, the HAM-D Depressed Mood Item, the Montgomery-Asberg D epression Rating Scale total score, and the Clinical Global Impression s Scale. Overall, a higher percentage of patients responded to venlafa xine than to placebo. Efficacy data indicated a dose-related response, most evident in the onset of clinical improvement; statistically sign ificant improvements in some primary parameters were seen as early as 1 to 2 weeks after initiation of treatment, especially in the 150- and 200-mg/day groups. These dose-related clinical improvements continued through week 12. Venlafaxine-treated patients who had depression asso ciated with anxiety showed significant dose-related improvements compa red with placebo-treated patients; improvement was noted by scores on the HAM-D Anxiety-Psychic Item and Anxiety-Somatization Factor. Few cl inically significant changes were observed in laboratory values, vital signs, or electrocardiogram tracings. Venlafaxine was generally well tolerated at all dosages. The most common study events included nausea , dizziness, somnolence, insomnia, dry mouth, and asthenia, which are consistent with findings of previous studies. The current study demons trated that 75 to 200 mg/day of venlafaxine twice daily produced a dos e-related improvement in the primary efficacy parameters and in the on set of significant antidepressant effects, which was noted at weeks 1 to 2 with the highest dosage tested (200 mg/day). The study also demon strated that these dosages of venlafaxine were safe and effective as f irst-line therapy for major depression and depression associated with anxiety.