Mirtazapine substitution in SSRI-induced sexual dysfunction

Background: Sexual side effects are a common and bothersome reaction to sel ective serotonin reuptake inhibitors (SSRIs), frequently leading to cessati on of treatment. Mirtazapine, an alpha(2)-adrenoceptor and serotonin-2/3 re ceptor antagonist, appears to cause few sexual problems. Method: Nineteen patients (12 women and 7 men), with SSRI-induced sexual dy sfunction who were in remission from major depressive disorder (total Hamil ton Rating Scale for Depression [HAM-D] score less than or equal to 10), we re switched to open-label mirtazapine for up to 6 weeks. Mirtazapine was ti trated from 7.5 mg to 45 mg daily, as tolerated. Sexual functioning was mea sured weekly with the Arizona Sexual Experiences Scale (ASEX), and depressi on was measured weekly with the HAM-D. Results: Eleven patients (58%) had a return of normal sexual functioning (m ean +/- SD ASEX score = 12 +/- 3), and another 2 (11%) reported significant improvement in sexual functioning (mean ASEX score reduced from 24 +/- 1 t o 20 +/- 0). All nineteen patients maintained their antidepressant response (HAM-D score after 6 weeks of mirtazapine = 6 +/- 3). The most commonly re ported side effects (using moderate/severe rating on a symptom checklist) w ere initial sedation (N = 3), irritability (N = 6), and muscle soreness and stiffness (N = 3). Weight gain of 10 to 20 Ib (4.5-9 kg) was seen in 3 pat ients (2 women and 1 man). Conclusion: Mirtazapine is an effective antidepressant for many patients ex periencing SSRI-induced sexual dysfunction.