OBJECTIVE:This study aims to evaluate the effects of intravaginal dehydroepiandrosterone (DHEA, prasterone) on the endometrium in postmenopausal women.METHODS:Intravaginal DHEA (6.5 mg) was administered daily for 52 weeks to 422 women who had endometrial biopsy at baseline and end of study, whereas 15 women were similarly treated for 26 to 52 weeks. Participants in three other studies received 3.25 mg (n = 126), 6.5 mg (n = 129), or 13 mg (n = 30) of DHEA for 12 weeks; women similarly had baseline and end-of-study biopsies. Endometrial biopsy samples were available for 668 women at baseline and end of study, with sufficient material for analysis.RESULTS:Endometrial atrophy or inactive endometrium (668 women) was found in all women treated with intravaginal DHEA. Similar atrophy was observed in 119 of 121 participants with sufficient material for analysis who received placebo.CONCLUSIONS:After cessation of estradiol secretion by the ovaries at menopause, the estrogens made by mechanisms of intracrinology are inactivated intracellularly at their site of formation and action, thus maintaining serum estradiol at biologically inactive concentrations to avoid stimulation of the endometrium. The absence of enzymes that are able to transform DHEA into estrogens in the endometrium explains the typical endometrial atrophy in all normal postmenopausal women in the presence of variable concentrations of circulating endogenous DHEA. According to these mechanisms, the inactive sex steroid precursor DHEA administered intravaginally acts exclusively in the vagina, whereas all serum sex steroids remain well within the biologically inactive postmenopausal reference range, thus avoiding any stimulation of the already atrophic endometrium.

Following the compelling data obtained in a pivotal phase III clinical trial performed in 218 postmenopausal women suffering from vaginal atrophy who received daily intravaginal 0.25, 0.5 or 1.0% DHEA (dehydroepiandrosterone) ovules for 12 weeks, we have performed analysis of the four co-primary objectives at each site of that multicentre U.S. and Canadian trial. Comparison was made of the change in percentage of parabasal and superficial cells, vaginal pH and severity of the most bothersome symptom. The site-by-site (seven sites) analysis has shown that 10–13 women per group are generally sufficient to obtain a significant or highly statistically significant decrease in vaginal pH and percentage of parabasal cells and increased percentage of superficial cells at p values ranging from 0.02 to <0.0001. For vaginal pain as the most bothersome symptom, a statistically significant difference from baseline was found at six out of seven sites. The exceptionally high consistency between all sites in this phase III study and high potency of the compound permit to obtain a clinically and statistically significant to highly significant effect of treatment on all parameters of vaginal atrophy with the 0.5% DHEA daily intravaginal dose which does not significantly affect the serum levels of oestrogens, thus avoiding systemic risks.

OBJECTIVE:Because a previous 1-week study has shown no or minimal changes in the serum levels of dehydroepiandrosterone (DHEA) and its metabolites after up to daily 1.8% (23.4 mg) intravaginal DHEA, the objective of the present study was to investigate the serum steroid levels during a 12-week daily intravaginal administration of 0%, 0.25%, 0.5%, and 1.0% DHEA (Prasterone) 1.3 mL ovules.METHODS:In a double-blind, placebo-controlled phase III study, 218 postmenopausal women (age range, 42-74 y) were randomized to receive daily one of four DHEA concentrations intravaginally. Serum steroids were measured by a Good Laboratory Practice-validated mass spectrometry technology in samples obtained at time of visit.RESULTS:The serum levels of DHEA and 11 of its metabolites measured at screening, day 1, and weeks 2, 4, 8, and 12 in women showed no or minimal changes during the whole observation period, with all values remaining well within the limits of normal postmenopausal women. No accumulation of the steroid metabolites nor change in DHEA bioavailability was detected.CONCLUSIONS:The present data show that local daily intravaginal DHEA administration at DHEA doses of 3.25-13 mg was able to rapidly and efficiently achieve correction of all the signs and symptoms of vaginal atrophy and improve sexual function and caused no or minimal changes in serum sex steroid levels, which all remain within the normal postmenopausal range, thus avoiding the risks of all estrogen formulations.

Objective: The objective of this study was to provide evidence that the transformation of DHEA into both androgens and/or estrogens locally in cells of the three layers of the vagina (epithelium, lamina propria, and muscularis) would have effects of greater impact, including effects on sexual function, than only effects on superficial epithelial cells as achieved with estrogens. Methods: This prospective, randomized, double-blind, and placebo-controlled phase III clinical trial has evaluated the effect of daily local intravaginal application of Prasterone (dehydroepiandrosterone; DHEA) for 12 weeks on the domains of sexual dysfunction, namely, desire/interest, arousal, orgasm, and pain at sexual activity, in 216 postmenopausal women with moderate to severe symptoms of vaginal atrophy. Results: A time- and dose-dependent improvement of the four domains of sexual function was observed. At the 12-week time interval, the 1.0% DHEA dose led, compared with placebo, to 49% (P = 0.0061) and 23% (P = 0.0257) improvements of the desire domains in the Menopause Specific Quality of Life and Abbreviated Sex Function questionnaires, respectively. Compared with placebo, the Abbreviated Sex Function arousal/sensation domain was improved by 68% (P = 0.006), the arousal/lubrication domain by 39% (P = 0.0014), orgasm by 75% (P = 0.047), and dryness during intercourse by 57% (P = 0.0001). Conclusions: By a local action in the vagina, DHEA applied daily at doses at which serum steroids remain well within normal postmenopausal values exerts relatively potent beneficial effects on all four aspects of sexual dysfunction. Such data indicate that combined androgenic/estrogenic stimulation in the three layers of the vagina exerts important beneficial effects on sexual function in women without systemic action on the brain and other extravaginal tissues.

OBJECTIVE:Because the secretion of dehydroepiandrosterone (DHEA), the exclusive source of sex steroids in postmenopausal women, is already decreased by 60% and continues to decline at the time of menopause, the objective of this study was to examine the effect of intravaginal DHEA on the symptoms and signs of vaginal atrophy.METHODS:This prospective, randomized, double-blind and placebo-controlled phase III clinical trial studied the effect of Prasterone (DHEA) applied locally in the vagina on the signs and symptoms of vaginal atrophy in 216 postmenopausal women.RESULTS:All three doses (0.25%, 0.5%, and 1.0%) of DHEA ovules applied daily intravaginally induced a highly significant beneficial change in the percentage of vaginal parabasal and superficial cells and pH as well as in the most bothersome symptom at 2 weeks. At the standard 12-week time interval, 0.5% DHEA caused a 45.9 +/- 5.31 (P < 0.0001 vs placebo) decrease in the percentage of parabasal cells, a 6.8 +/- 1.29% (P < 0.0001) increase in superficial cells, a 1.3 +/- 0.13 unit (P < 0.0001) decrease in vaginal pH, and a 1.5 +/- 0.14 score unit (P < 0.0001) decrease in the severity of the most bothersome symptom. Similar changes were seen on vaginal secretions, color, epithelial surface thickness, and epithelial integrity. Comparable effects were observed at the 0.25% and 1.0% DHEA doses.CONCLUSIONS:Local Prasterone, through local androgen and estrogen formation, causes a rapid and efficient reversal of all the symptoms and signs of vaginal atrophy with no or minimal changes in serum steroids, which remain well within the normal postmenopausal range. This approach avoids the fear of systemic effects common to all presently available estrogen formulations and adds a novel physiological androgenic component to therapy.