Ana Maria Salvatierra

Immediate pre-ovulatory administration of 30 mg ulipristal acetate significantly delays follicular rupture

BACKGROUND Current methods of hormonal emergency contraception (EC) are ineffective in preventing follicular rupture when administered in the advanced pre-ovulatory phase. This study was designed to determine the capacity of ulipristal acetate (UPA), a selective progesterone receptor modulator developed for EC, to block follicular rupture when administered with a follicle of >or=18 mm. METHODS This was a double-blind, crossover, randomized, placebo-controlled study. Thirty-five women contributed with UPA (30 mg. oral) and a placebo cycle. Serial blood sampling for luteinizing hormone (LH), estradiol and progesterone measurements and follicular monitoring by ultrasound were performed before and for 5 days following treatment. Follicular rupture inhibition was assessed in the overall study population and in subgroups of women stratified by when treatment was administered in relation to LH levels (before the onset of the LH surge, after the onset of the surge but before the LH peak or after the LH peak). RESULTS Follicular rupture failed to occur for at least 5 days following UPA administration in 20/34 cycles [59%; 95% confidence interval (CI) (40.7-75.4%)], whereas rupture took place in all cycles within 5 days of placebo intake. When UPA was administered before the onset of the LH surge, or after the onset but before the LH peak, follicle rupture had not occurred within 5 days in 8/8 (100%) and 11/14 [78.6%; 95% CI (49.2-95.3)] cycles, respectively. In contrast, when UPA was given after the LH peak, follicle rupture inhibition was only observed in 1/12 [8.3%; 95% CI (0.2-38.5)] cycles. CONCLUSIONS This study demonstrates that UPA can significantly delay follicular rupture when given immediately before ovulation. This new generation EC compound could possibly prevent pregnancy when administered in the advanced follicular phase, even if LH levels have already begun to rise, a time when levonorgestrel EC is no longer effective in inhibiting ovulation.

New insights on the mode of action of intrauterine contraceptive devices in women

To gain a better understanding of the mechanism of action of intrauterine devices (IUDs), a search was made for ova in the genital tracts of 115 women using no contraception and of 56 women using IUDs, all of whom volunteered for study in conjunction with surgical sterilization. Ova were recovered from tubal flushings between 48 and 120 hours after the midcycle peak of luteinizing hormone in 39% of the IUD users compared with 56% of women in the control group (0.05 less than P less than 0.10). This suggests an action of the IUD before the ovum reaches the uterus. Eggs with a microscopic appearance consistent with fertilization were recovered from the fallopian tubes of half of the women using no contraception who had intercourse within the fertile period of the reproductive cycle and from whom ova were recovered. In contrast (P less than 0.01), no eggs with this appearance were recovered in IUD users who had intercourse within the fertile period. No ova were recovered from the body of the uterus of any of the IUD users. Fertilized ova are less likely to reach the uterine cavity containing an IUD. Thus, the principal mode of IUDs is by a method other than destruction of live embryos.

Effects of the Yuzpe regimen, given during the follicular phase, on ovarian function

This study was conducted to assess to what extent the Yuzpe regimen, or half the dose, given in the follicular phase, prevents ovulation during the ensuing 5 days. Sixty women were divided into six groups. All groups received placebo in one cycle and drug in another, in a randomized order. Groups differed by the dose and size of the leading follicle at the time of treatment (12-14, 15-17, or 18-20 mm). Ovulation was absent during the ensuing 5 days in 13 of 20 participants (65%) and in 8 of 20 participants (40%) who received the full and the half dose, respectively, when follicles were 12-17 mm. No ovulation occurred, within the critical period, in 7 of 39 placebo cycles (18%). When follicles were 18-20 mm, treatment did not prevent ovulation. In most drug-treated cycles, plasma gonadotropin and sex steroid levels were significantly depressed within the 5-day period, even when follicular rupture occurred within that period. In conclusion, the Yuzpe regimen can suppress or postpone ovulation to an extent that exceeds the fertile life of spermatozoa. Lack of ovulation within the critical period and dysfunction of the ovulatory process probably account for the contraceptive effect of this method in most cases. The present data do not warrant the use of half the dose of the Yuzpe regimen.

Colposcopic evaluation of a vaginal gel formulation of iota-carrageenan

There is an urgent need to develop safe, effective, and acceptable vaginal products for the prevention of sexually transmitted infections. Preliminary in vitro results suggest that vaginal formulations of sulfated polysaccharides, including iota-carrageenan, have the potential to block mucosal transmission of human immunodeficiency virus (HIV). Twenty-five women in five sites participated in Phase I trials to evaluate the safety of a formulation containing iota-carrageenan (PC 213). The results of this study indicate that a 5 mL 2% gel formulation of iota-carrageenan is not associated with significant irritation of the female reproductive tract when administered once daily in the absence of sexual intercourse. Given the small number of participants in this initial study, careful observation for potential irritation must also be included in larger studies of this and other vaginal formulations.

Suppression of follicular rupture with meloxicam, a cyclooxygenase-2 inhibitor: potential for emergency contraception

BACKGROUND There is evidence that cyclooxygenase-2 (COX-2) inhibitors can prevent or delay follicular rupture. COX-2 inhibitors, such as meloxicam, may offer advantages over emergency contraception with levonorgestrel, such as extending the therapeutic window for up to 24 h. We assessed the effect of meloxicam administered in the late follicular phase upon ovulation in women. MATERIALS AND METHODS This was a single center, double blind, crossover study designed to assess the effects in 27 eligible women (18-40 years old, surgically sterilized with regular menstrual cycles) of meloxicam, 15 or 30 mg/day, administered orally for five consecutive days during the late follicular phase, starting when the leading follicle reached 18 mm diameter. Volunteers underwent two treatment cycles separated by one resting cycle, with randomization to dose sequence. Main outcomes were follicular rupture; serum LH, progesterone and estradiol (E2) levels; and incidence of adverse events. RESULTS Twenty-two volunteers completed the study. There were no differences between meloxicam doses in menstrual cycle length. Dysfunctional ovulation was observed in 11/22 (50%) cycles treated with 15 mg/day and 20/22 (90.9%) cycles with 30 mg/day (P = 0.0068). All women had normal luteal phase progesterone levels; mean maximal values +/- SEM were 42 +/- 4.1 and 46.8 +/- 2.6 nmol/l for 15 and 30 mg/day groups, respectively. There were no serious adverse events, and no changes in LH and E2 levels or in cycle length. CONCLUSIONS Meloxicam 30 mg given for five consecutive days in the late follicular phase is safe, effective and may be an alternative form of emergency contraception.

Pharmacokinetics and bioavailability of ST 1435 administered by different routes

The ovulation inhibiting potency of the synthetic progestin ST 1435 (Nestorone) is high after parenteral administration and practically nil after oral administration. The purpose of this study was to determine the pharmacokinetic parameters of ST 1435 after single oral or intravenous administration or after long-term treatment with subdermal implants in women. After administration, as a single i.v. bolus, the plasma disappearance rate of immunoreactive ST 1435 had two components with half-lives (mean +/- SE) of 3.5 +/- 0.5 and 83 +/- 14 min, respectively. The volume of distribution was 4.7 +/- 1.3 L/Kg and the metabolic clearance rate was 55 +/- 6 L/Kg/d. After oral administration, the bioavailability was about 10% of the dose. After chronic subdermal administration, the plasmatic clearance was slower than following the acute doses. These results show that ST 1435 has shorter half-lives and a faster clearance rate than progestins which bind SHBG. The large volume of distribution indicates accumulation in the extravascular space and was expected in view of the high affinity of ST 1435 for progesterone receptors. The slower plasma elimination rate after chronic administration was attributed to the re-entry of a larger mass of drug from the extravascular space, and/or accumulation of immunoreactive metabolites with slower clearance than the parent steroid.

Ovarian function during use of Nestorone® subdermal implants

Nestorone(R) progestin (NES) is a potent 19-nor-progesterone derivative which is biologically inactive when administered orally; however, it is an excellent option for implant contraception. The objective of this study was to evaluate ovarian function during use of either one 4-cm or two 3-cm NES implants for 24 months. A total of 60 volunteers were enrolled in each dose group. Vaginal ultrasound (VUS) and blood sampling for determinations of estradiol (E(2)), progesterone (P) and NES serum levels were carried out twice a week for 6 consecutive weeks, beginning in months 1, 6, 12, 18, and 24 of implant use. Serum levels of NES declined with time, with a more pronounced decrease during the first 18 months of implant use; thereafter, NES levels remained stable until the end of the study at 24 months. Luteal activity was very infrequent during the first year of use (<3%) but increased during the second year, occurring in 27% and 35% of the sampling periods in the 1-implant group, and 2% and 16% of the sampling periods in the 2-implant group, at months 18 and 24 of use, respectively. No luteal activity was observed with NES levels above 80 pmol/L. Serum P levels in periods of luteal activity were significantly lower than those of controls. Persistent anovulatory follicles were the most common VUS finding and this was associated with E(2) levels that remained within the normal range (101-1500 pmol/L) in the majority of the sampling periods studied. Considering that a single implant offers advantage for insertion and removal, a new single NES implant is being developed with a slightly higher release rate, to reduce effectively the incidence of ovulation and provide a greater margin of safety beyond 2 years.

A prospective, open-label, multicenter study to assess the pharmacodynamics and safety of repeated use of 30 mg ulipristal acetate

OBJECTIVE Ulipristal acetate (UPA) 30 mg is safe and effective for emergency contraception (EC). This prospective open-label exploratory study was conducted to obtain additional data on the pharmacodynamic effects of repeated dose of UPA 30 mg during an 8-week period (effects on ovulation inhibition, hormonal levels, endometrium and cervical mucus). Safety and tolerability data of repeated use of UPA EC were also collected. STUDY DESIGN A total of 23 healthy female, healthy sterilized women participated in two substudies receiving UPA for 8 consecutive weeks. In substudy 1, UPA 30 mg was administered every 7 days (Q7D n=12); while in substudy 2, every 5 days (Q5D n=11). Subjects were monitored three times a week in a baseline cycle and during treatment with transvaginal ultrasounds, hormonal measurements and cervical mucus evaluation. Laboratory safety measurements and standard surrogate thrombosis risk markers were measured at baseline and within a few days of the last tablet. A luteal phase endometrial biopsy was taken in the baseline cycle and posttreatment. RESULTS A total of 11/12 (91.7%) and 8/11 (72.7%) of the subjects ovulated at least once in substudy Q7D and Q5D, respectively, with similar, normal hormonal profiles. No effect on cervical mucus was observed. All biopsies were classified as benign in both substudies; 5/11 biopsies on Q5D posttreatment were classified as nonphysiological with some of typical progesterone receptor modulator-associated endometrial changes. UPA was well tolerated in both treatment arms while clinical laboratory results and surrogate thrombosis markers were reassuring. CONCLUSIONS Repeat use of 30 mg oral UPA every 5 or 7 days for 8 weeks initially delays follicular rupture but ovulation eventually occurs with time in most subjects. Safety data indicate that UPA 30 mg could be safely administered if needed more than once for EC in a given menstrual cycle. IMPLICATIONS These data demonstrate that repeated use of UPA 30 mg is safe. However, ovulation eventually occurs in a high proportion of women in spite of repeated treatments in both studied regimens. Nevertheless, since the stage of follicular development of women seeking initial or repeat EC use is generally unknown, the repeated use of UPA may still delay follicular rupture and prevent an unintended pregnancy in the event of further unprotected intercourse.

Effects of a sequential regimen of mifepristone-medroxyprogesterone acetate on ovarian function, endometrial development and hormonal parameters.

The efficacy of a low dose of mifepristone, 5 mg/day for the first 15 days of the menstrual cycle, followed by medroxy-progesterone acetate (MPA), 10 mg/day for the next 13 days, for inhibiting ovulation was assessed in ten volunteers who were treated for three successive cycles. Hormonal determinations in blood and urine samples, ovarian ultrasonography and an endometrial biopsy taken on day 21-24 of the third treatment cycle were used to monitor the cycles. Ovulation was confirmed in 11 of the 30 treated cycles and, in these 11, the LH peak and follicular rupture occurred during MPA treatment periods. Out of 19 anovulatory cycles, 16 had no increase in progesterone levels and another 3 developed a luteinized unruptured follicle. Progestin administration induced secretory changes in the endometrium, but irregular or delayed development was found. Regular withdrawal bleeding occurred in all subjects. These data indicate that the sequential regimen can suppress ovulation while maintaining regular bleeding but increased efficacy is needed for phase II clinical trials.

Effect of oral administration of a continuous 18 day regimen of meloxicam on ovulation: experience of a randomized controlled trial.

BACKGROUND Cyclooxygenase-2 (COX-2) is expressed in all female reproductive organs. Therefore, inhibitors of COX-2 may affect reproductive function. We evaluated the effect of extended administration of meloxicam on ovulation and the menstrual cycle. Our hypothesis was that meloxicam administered from menstrual cycle day 5- 22 could interfere with follicular rupture, without disrupting the menstrual cycle, and could be a potential non-hormonal contraceptive method. METHODS The study was conducted in 56 healthy sterilized women. Before the onset of treatment and after the end of treatment, participants were observed during a control cycle to ensure that they had progesterone (P₄) serum levels (>12 nmol/l) consistent with ovulation. Participants were treated for 18 days, during three consecutive cycles. They were randomized to 15 or 30 mg/day. The menstrual cycle was monitored with serial ultrasound and hormone assays in blood. RESULTS Fifty-six volunteers completed the study. In 55% of cycles treated with 15 mg/day and in 78% of cycles treated with 30 mg/day (p<0.001) we observed dysfunctional ovulation defined as follicular rupture not preceded 24-48 h earlier by an LH peak or preceded by a blunted LH peak (<21 IU/l) or not followed by an elevated serum P₄ level >12 nmol/l. Ovulation was observed in 44.6% and in 21.7% of women in the lower dose group and the higher dose group, respectively. There were no differences between the two doses in other parameters measured. There were no serious adverse events and adverse events were not different between doses or between control and treated cycles. CONCLUSIONS Although administration of meloxicam on menstrual cycle days 5- 22 resulted in a dose-dependent inhibition of ovulation, more than 20% of subjects had normal ovulation with the highest dose. IMPLICATIONS Previous studies have shown that oral meloxicam can delay follicle rupture. This study investigated daily oral meloxicam as a non-hormonal contraceptive. Since ovulation occurs in over 20% of cycles even with a high dose of 30 mg daily, it is not likely that the approach would be a highly effective contraceptive strategy.