Selective serotonin re-uptake inhibitor treatment-emergent sexual dysfunction: randomized double-blind placebo-controlled parallel-group fixed-dose study of a potential adjuvant compound, VML-670

Abstract

Sexual dysfunction is common during acute and continuation treatment of depressed patients with selective serotonin (5-hydroxytryptamine, 5-HT) re-uptake inhibitors (ssRIs), but there is no consensus on clinical management. Compounds with 5-HT1A agonist properties have been proposed as adjuvant agents in patients continuing with ssRIs. Randomized double-blind placebo-controlled parallel-group fixed-dose 4-week treatment study. Previously depressed male or female patients in symptomatic remission receiving stable doses of fluoxetine or paroxetine but experiencing treatment-emergent sexual dysfunction were randomised to double-blind treatment with placebo or VML-670 (a 5-HT1A and 5-HT1D agonist). sexual dysfunction was assessed by the Arizona sexual Experiences scale (ASEX). Two-hundred and eighty-eight patients (204 women, 84 men; mean age 44.2 years) received VML-670 ( n = 149; 107 women, 42 men) or placebo ( n = 139; 97 women, 42 men). In the intention-to-treat, last-observation carried forward analysis ( n = 282), proportionately more patients became free of sexual dysfunction with VML-670 (34.3% versus 27.9% with placebo) but this difference was not statistically significant. Male patients treated with VML-670 showed a significantly greater ( p =0.01) improvement in ability to achieve and maintain penile erection (a secondary outcome measure). A similar proportion of patients reported on-treatment, treatment-emergent adverse events with VML-670 (71.1%) and placebo (68.3%), and a similar proportion experienced at least one treatment-related adverse event (36.9% versus 35.3%). Double-blind treatment with VML-670 offered no significant advantage over placebo on the primary outcome measure in the overall sample. Further studies may be warranted in larger groups of male patients with sexual dysfunction.