BACKGROUND: This was an 8-week, multicenter,
randomized, double-blind, parallel-group study of the efficacy and
tolerability of venlafaxine and fluoxetine.
METHOD: Outpatients with DSM-III-R major
depression, a minimum score of 20 on the 21-item Hamilton Rating Scale for
Depression (HAM-D), and depressive symptoms for at least 1 month were
eligible. Patients were randomly assigned to treatment with venlafaxine,
37.5 mg twice daily, or fluoxetine, 20 mg once daily. The dose could be
increased to venlafaxine, 75 mg twice daily, or fluoxetine, 20 mg twice
daily, after 3 weeks for a poor response. The primary efficacy variables
were the final on-therapy scores on the HAM-D, Montgomery-Asberg Depression
Rating Scale (MADRS), and Clinical Global Impressions Severity of Illness
(CGI-S) and Improvement (CGI-I) scales.
RESULTS: Three hundred eighty-two patients
were randomly assigned to therapy and included in the intent-to-treat
analysis. Both venlafaxine and fluoxetine produced significant reductions
from baseline to day 56 in mean HAM-D, MADRS, and CGI-S scores, but no
significant differences were noted between groups. Among patients who
increased their dose at 3 weeks, significantly (p < .05) more patients
taking venlafaxine than taking fluoxetine had a CGI-I score of 1 (very much
improved) at the final evaluation. The most frequent adverse events were
nausea, headache, and dizziness with venlafaxine and nausea, headache, and
insomnia with fluoxetine.
CONCLUSION: These results support the
efficacy and tolerability of venlafaxine in comparison with fluoxetine for
treating outpatients with major depression.