Influence of treatment of vulvovaginal atrophy with intravaginal prasterone on the male partner.

OBJECTIVE: The aim was to analyze the opinion of the male partner of women treated for vulvovaginal atrophy (VVA) with intravaginal 0.50% DHEA (prasterone), thus providing information on both members of the couple. METHODS: On a voluntary basis, in a prospective, randomized, double-blind and placebo-controlled phase-III clinical trial, the male partner filled a questionnaire at baseline and at 12 weeks stating his observations related to his penis and intercourse before and after VVA treatment. RESULTS: Sixty-six men having a partner treated with intravaginal DHEA and 34 others having a partner treated with placebo answered the questionnaires. Concerning the feeling of vaginal dryness of their female partner, the severity score following DHEA treatment improved by 81% (0.76 units) over placebo (p = 0.0347). Thirty-six percent of men having a partner treated with DHEA did not feel the vaginal dryness of the partner at the end of treatment compared to 7.8% in the placebo group. When analyzing the situation at 12 weeks compared to baseline, an improved score of 1.09 units was the difference found for the DHEA group compared to 0.76 for the placebo group (p = 0.05 vs. placebo). In the DHEA group, 38% of men scored very improved compared to 18% in the placebo group. No adverse event has been reported. CONCLUSION: The male partner had a very positive evaluation of the treatment received by his female partner.

Decreased efficacy of twice-weekly intravaginal dehydroepiandrosterone on vulvovaginal atrophy.

OBJECTIVE: While daily intravaginal administration of 0.50% (6.5 mg) dehydroepiandrosterone (DHEA, prasterone) for 12 weeks has shown clinically and statistically significant effects on moderate to severe (MS) dyspareunia as the most bothersome symptom (MBS), the present study analyzes the effect of a reduced dosing regimen on MBS vaginal dryness. METHOD: Daily intravaginal 0.50% prasterone for 2 weeks followed by twice weekly for 10 weeks versus placebo. RESULTS: Maximal beneficial changes in vaginal parabasal and superficial cells and pH were observed at 2 weeks as observed for intravaginal 10 µg estradiol (E2). This was followed by a decrease or lack of efficacy improvement after switching to twice-weekly dosing. The decrease in percentage of parabasal cells, increase in percentage of superficial cells and decrease in vaginal pH were all highly significant (p < 0.0001 to 0.0002 over placebo) at 12 weeks. In parallel, the statistical significance over placebo (p value) on MBS vaginal dryness at 6 weeks was 0.09 followed by an increase to 0.198 at 12 weeks. For MBS dyspareunia, the p value of 0.008 at 6 weeks was followed by a p value of 0.077 at 12 weeks, thus illustrating a decrease of efficacy at the lower dosing regimen. The improvements of vaginal secretions, color, epithelial integrity and epithelial surface thickness were observed at a p value < 0.01 or 0.05 over placebo at 2 weeks, with a similar or loss of statistical difference compared to placebo at later time intervals. No significant adverse event was observed. Vaginal discharge related to the melting of Witepsol was reported in 1.8% of subjects. CONCLUSION: The present data show that daily dosing with 0.50% DHEA for 2 weeks followed by twice-weekly dosing is a suboptimal treatment of the symptoms/signs of vulvovaginal atrophy resulting from a substantial loss of the efficacy achieved at daily dosing.

Probing the interaction between inactivation gating and Dd-sotalol block of HERG.

Potassium channels encoded by HERG underlie I:(Kr), a sensitive target for most class III antiarrhythmic drugs, including methanesulfonanilides such as Dd-sotalol. Recently it was shown that these drugs are trapped in the channel as it closes during hyperpolarization. At the same time, HERG channels rapidly open and inactivate when depolarized, and methanesulfonanilide block is known to develop in a use-dependent manner, suggesting a potential role for inactivation in drug binding. However, the role of HERG inactivation in class III drug action is uncertain: pore mutations that remove inactivation reduce block, yet many of these mutations also modify the channel permeation properties and could alter drug affinity through gating-independent mechanisms. In the present study, we identify a definitive role for inactivation gating in Dd-sotalol block of HERG, using interventions complementary to mutagenesis. These interventions (addition of extracellular Cd(2+), removal of extracellular Na(+)) modify the voltage dependence of inactivation but not activation. In normal extracellular solutions, block of HERG current by 300 micromol/L Dd-sotalol reached 80% after a 10-minute period of repetitive depolarization to +20 mV. Maneuvers that impeded steady-state inactivation also reduced Dd-sotalol block of HERG: 100 micromol/L Cd(2+) reduced steady-state block to 55% at +20 mV (P:<0.05); removing extracellular Na(+) reduced block to 44% (P:<0.05). An inactivation-disabling mutation (G628C-S631C) reduced Dd-sotalol block to only 11% (P:<0.05 versus wild type). However, increasing the rate of channel inactivation by depolarizing to +60 mV reduced Dd-sotalol block to 49% (P:<0.05 versus +20 mV), suggesting that the drug does not primarily bind to the inactivated state. Coexpression of MiRP1 with HERG had no effect on inactivation gating and did not modify Dd-sotalol block. We postulate that Dd-sotalol accesses its receptor in the open pore, and the drug-receptor interaction is then stabilized by inactivation. Whereas deactivation traps the bound methanesulfonanilide during hyperpolarization, we propose that HERG inactivation stabilizes the drug-receptor interaction during membrane depolarization.