A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Medicine in the branch of Psychiatry Melbourne, 2005 / Sexual dysfunction is a common side effect of treatment with antidepressants, particularly those with a serotonergic action. The problem has significant implications for a patient’s quality of life and their compliance with medication. Given the often longterm nature of depressive disorders and their treatment this side effect poses a potential management challenge and may have serious prognostic implications. There are currently few evidence-based treatment strategies for the management of antidepressant induced sexual dysfunction. This study was conducted to evaluate the usefulness of granisetron, a serotonin type-3 receptor antagonist, in the treatment of women experiencing sexual dysfunction due to serotonergic antidepressants. Twelve women with antidepressant induced sexual dysfunction were assigned to receive either granisetron (N=5) or placebo (N=7) in a 14-day randomised, double blind, placebo controlled drug trial. Two subjects in the granisetron group did not complete the study. Each subject’s sexual functioning was assessed at baseline, day 7 and day 14 using both the Arizona Sexual Experience Scale and the Feiger Sexual Function and Satisfaction Questionnaire. No statistical differences were measured either at baseline or at endpoint between the granisetron and placebo groups. The study did not produce evidence supporting the usefulness of granisetron as an adjunctive medication in women with antidepressant induced sexual dysfunction. Furthermore, this finding does not suggest a primary role for the serotonin type-3 receptor in the pathogenesis of this side effect.