Twelve randomised placebo-controlled trials of vortioxetine were included; all trials were conducted by the manufacturer of vortioxetine. Participant completion rates ranged from 74% to 90%. Follow-up data at six-to-eight weeks were analysed. Nine trials were of non-elderly patients and reported their changes in MADRS or HRSD-24; one trial was of elderly patients only; and two trials did not report outcome data.
Four of the nine trials on non-elderly patients found no difference between vortioxetine and placebo; two had an active comparator – one found no differences and one found a difference for the active comparator only (negative trial). The other five trials were considered positive for vortioxetine at doses of 1mg per day (one trial), 5mg per day (two trials), 10mg per day (two trials), 15mg per day (one trial), and 20mg per day (three trials). Two of these trials were positive for vortioxetine 20mg, but not for 10mg (one trial) or 15mg (one trial). The trial of elderly patients found a statistically significant difference between vortioxetine and placebo, at eight weeks, on the HRSD-24.
In placebo-controlled trials that also had an active comparator, duloxetine 60mg per day (three trials) and venlafaxine 225mg per day (one trial) had more favourable results, for response and remission, than vortioxetine at any dose. One trial, without placebo, compared vortioxetine with agomelatine and found a statistically significant difference, in MADRS score at 12 weeks, favouring vortioxetine.
The number needed to harm, for discontinuation of vortioxetine due to an adverse event, was 36 (95% CI 24 to 70). Compared with placebo, the most common adverse events (incidence 5% or more, and at least twice the rate of placebo) were nausea (NNH 6, 95% CI 6 to 7), constipation (NNH 64, 95% CI 37 to 240) and vomiting (NNH 28, 95% CI 23 to 38). The author reported that changes in weight were not clinically significant. Further results were reported.