Why this study matters

Dextromethorphan-bupropion is a safe and effective pharmacotherapeutic agent for major depressive disorder with a novel mechanism of action and rapid onset.

Study design

This double-blind, phase 3 trial involved 327 patients with major depressive disorder. The Montgomery-Asberg Depression Rating Scale was used to compare the treatment responses to dextromethorphan-buproprion and placement.

Results and conclusion

Of 327 patients enrolled in the phase 3 GEMINI study, 163 patients were treated with dextromethorphan-bupropion (45 mg-105 mg tablet) and 164 patients received a placebo (1 tablet daily x 3 d, then twice daily x 6 weeks).

Symptom remission was achieved in 39.5% and 17.3% of patients treated with dextromethorphan-bupropion and placebo, respectively. Symptom remission in the dextromethorphan-bupropion group occurred as early as week 1 of treatment.

A clinical response occurred in 54.0% and 34.0% of patients treated with dextromethorphan-bupropion and placebo, respectively.