A randomized, double-blinded, placebo-controlled study to evaluate the efficacy and safety of venlafaxine extended release in Japanese patients with generalized anxiety disorder.

AIM: The current study investigated the superiority of anxiolytic effects of venlafaxine extended release (ER) compared with placebo and its safety and tolerability in Japanese adult outpatients with generalized anxiety disorder (GAD).

METHODS

In this placebo-controlled, double-blind study, 357 eligible participants were randomized to receive venlafaxine ER (75-225 mg/day) or placebo for 8 weeks. The primary endpoint was change from baseline to week 8 in Hamilton Anxiety Rating Scale (HAM-A) total score. Secondary endpoints included changes from baseline to week 8 in scores of HAM-A psychic anxiety factors, HAM-A somatic anxiety factors, Clinical Global Impressions-Severity of Illness (CGI-S), Generalized Anxiety Disorder-7 (GAD-7), Zung Self-Rating Anxiety Scale (Z-SAS), Sheehan Disability Scale (SDS), and the absolute score of Clinical Global Impressions-Global Improvement (CGI-I).

RESULTS

Venlafaxine ER showed statistically significant reduction in HAM-A total score at week 8 (difference versus placebo: P = 0.012). The results of all secondary endpoints were consistent with this finding and likewise demonstrated statistical significance in favor of venlafaxine ER in investigator- and patient-rated scales. Venlafaxine ER further showed statistically significant remission in total HAM-A score. These results showed that venlafaxine ER improved patients' functional disabilities along with symptoms more than placebo. Venlafaxine ER was well tolerated, and safety findings were generally consistent with the known safety profile of the drug.

CONCLUSION

Venlafaxine ER has a favorable benefit-risk profile in adult Japanese patients with GAD, indicating its potential to improve GAD symptoms as well as patients' function and exert superior anxiolytic effects over placebo without any new safety concern.

TRIAL REGISTRATION: Japan Registry of Clinical Trials Identifier jRCT2031220156.