A 6-month prospective observational study on the effects of quetiapine on sexual functioning

The aim of this study was to assess the long-term impact of quetiapine on sexual functioning of patients with schizophrenia treated in a real practice setting.

This was a multicenter, noncomparative, open-label, and naturalistic study conducted in outpatients with a diagnosis of schizophrenia or schizophreniform disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Patients were evaluated at baseline, day 15, and at the end of months 1, 3, and 6 using the Brief Psychiatry Rating Scale, the Clinical Global Impression Severity and Improvement Scales, and the Psychotropic-Related Sexual Dysfunction Questionnaire. All primary effectiveness analyses were based on the intent-to-treat sample and consisted primarily of last-observation-carried-forward analysis of Psychotropic-Related Sexual Dysfunction Questionnaire, Brief Psychiatry Rating Scale, and Clinical Global Impression Improvement of Illness Scale.

Eighty-six patients were recruited by 19 investigators, and 82 patients were included in the intent-to-treat sample. Psychotropic-Related Sexual Dysfunction Questionnaire total scores for the patients decreased progressively and significantly from baseline to the study end point. When only patients who initiated quetiapine treatment without being switched from another antipsychotic (n = 28) were included in the intent-to-treat analysis, Psychotropic-Related Sexual Dysfunction Questionnaire scores remained almost unchanged throughout the study. Sexual dysfunction rates, defined as a change in the score of any item greater than 0, were 3.7%, 2.4%, 2.4%, and 4.9% for decreased libido, delayed ejaculation/orgasm, lack of ejaculation/orgasm, and difficulties with erection/lubrication, respectively. Overall, quetiapine was efficacious and well tolerated.

Despite the limitations of the design, our results suggest that quetiapine shows a low frequency of sexual dysfunction during long-term treatment of patients with schizophrenia or schizophreniform disorder in the clinical practice setting.