The incidence of treatment-emergent sexual dysfunction increased with the dose of vortioxetine. Note: generally if as A increases, B increases, this suggests that A really is related to B.
The incidences of treatment-emergent sexual dysfunction were as follows: placebo 32%, vortioxetine 5 mg 26%, vortioxetine 10 mg 35%, vortioxetine 15 mg 43%, and vortioxetine 20 mg 46%, duloxetine 48%.
Statistically, vortioxetine 5 mg was specifically shown to be “non-inferior” to placebo in terms of causing treatment-emergent sexual dysfunction.
Vortioxetine 10, 15, and 20 mg did not meet that higher criterion for being shown to be non-inferior to placebo. But these higher doses were not shown to cause more treatment-emergent sexual dysfunction than placebo either. Put together, what this means is that we can’t be sure either way whether or not the incidence of treatment-emergent sexual dysfunction with vortioxetine 10, 15, and 20 mg is equal to that with placebo.
Persons receiving duloxetine 60 mg/day had greater treatment-emergent sexual dysfunction than persons receiving vortioxetine 5 mg/day or 10 mg/day . But that sexual dysfunction was not more than that with vortioxetine 15 mg/day or 20 mg/day.
A different way of looking at treatment-emergent sexual dysfunction is to look at worsening of sexual functioning in the persons who already had sexual dysfunction prior to starting in the study. These were over 70% of the patients. None of the doses of vortioxetine had statistically significantly greater worsening of sexual dysfunction than placebo, but duloxetine did.
Now, you may say to yourself that you are not familiar with the Arizona Sexual Experiences Scale and are not sure what the cut offs of this questionnaire really mean. In that case, a simpler (though less statistically powerful) way is to ask: what percentages of patients came in and when asked how they were doing, spontaneously reported that they had some form of treatment-emergent sexual dysfunction. The percentages of persons reporting at least one adverse event related to sexual dysfunction were: placebo 1%, vortioxetine 2.2%, duloxetine 5.7%. But keep in mind that these percentages refer to when the persons were not specifically asked about sexual dysfunction but spontaneously reported it. That method of eliciting sexual dysfunction is notorious for failing to identify many persons with sexual dysfunction.