Tibolone and transdermal E2/NETA for the treatment of female sexual dysfunction in naturally menopausal women: results of a randomized active-controlled trial.

INTRODUCTION There are some data to suggest that tibolone improves sexual function in postmenopausal women. However, evidence about the effects of tibolone on female sexual dysfunction is lacking. AIM To compare the efficacy on sexual function of tibolone 2.5 mg to continuous combined transdermal estradiol (E2)/norethisterone acetate (NETA) (50 microg/140 microg) in naturally postmenopausal women with sexual dysfunction. MAIN OUTCOME MEASURE Differences between treatment groups in the change from baseline for the composite subscore of the arousal, desire, and satisfaction domains of the self-reported Female Sexual Function Index (FSFI). METHODS A multicenter, double-blind, randomized, clinical trial was performed. Sexual function was assessed with the FSFI at baseline, week 12, and week 24. The outcomes of the Female Sexual Distress Scale (FSDS) and the frequency of satisfying sexual events (daily diaries) were secondary end points. RESULTS Four hundred three women, mean age 56, were included. Both therapies improved sexual function assessed by the FSFI. In the per protocol analysis, but not in the intent-to-treat analysis, the increase in FSFI scores was significantly larger in the tibolone group when compared with the E2/NETA patch group at week 24 (P = 0.036 and P = 0.025 for the composite subscore and total FSFI score, respectively). The satisfying sexual event rate increased from three to four times per 28 days at week 24 (P < 0.001 from baseline for both groups), with no difference between groups. The FSDS showed a significant decrease from baseline (P < 0.001), which was comparable for both treatment groups. CONCLUSIONS Both treatments resulted to improved overall sexual function, as determined by scores on the FSFI, an increase in the frequency of sexual events, and a reduction in sexuality-related personal distress. The statistically significant higher FSFI scores in the tibolone group, when compared to the E2/NETA group, may be because of tibolone's combined estrogenic and androgenic properties.