Comparison of two dosage regimens of fluoxetine in major depression.

The effect of dose frequency on fluoxetine efficacy and safety was evaluated in a double-blind study in patients with major depressive disorder. The patients received fluoxetine once a day (in the morning) or twice a day (in the morning and at noon). There were no significant differences between the two groups in the mean measures of efficacy, all of which showed significant improvement over baseline (p less than .001). Adverse experience profiles were not significantly different, with nervousness/anxiety predominating in both groups. In the subsequent 48-week open-label study, the percentage of patients reporting adverse experiences decreased greatly.