Serotonergic targets in the treatment of antidepressant induced sexual dysfunction: a pilot study of granisetron and sumatriptan

Antidepressant induced sexual dysfunction is a common adverse event that is particularly evident with serotonergic antidepressants. There is a paucity of clinical trial evidence on the treatment of this problem. While there is some evidence of involvement of the serotonin (5-HT2) receptor subtype in this phenomenon, other serotonergic receptor systems are not well studied. In this trial, 35 patients on maintenance therapy with a variety of serotonergic antidepressants, who reported antidepressant induced sexual dysfunction, were enrolled. Patients were given both granisetron 1 mg, and sumatriptan 100 mg, in a crossover design, to be used 1 h before intercourse. Sexual dysfunction was measured using the Feiger scale. There was a high dropout rate in the trial, reflecting both embarrassment with the pharmacological treatment of sexual dysfunction and difficulties with planning and timing the medication. Nevertheless, there was a significant effect of granisetron in this study, with scores decreasing from 23.7 (SD 2.52) to 16.0 (SD 6.42) on the Feiger scale (n = 14, P = 0.001, Wilcoxon sign rank test). Sumatriptan failed to show a significant change from baseline at the 0.01 level of significance. While the small sample size, high dropout rates and open label design are limitations to this study, it suggests efficacy of the granisetron in antidepressant induced sexual dysfunction and the role of the 5-HT3 receptor in this phenomenon.