Pituitary–ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75-mg dose given on the days preceding ovulation

Croxatto, Horacio B.; Brache, Vivian; Pavéz, Margarita; Cochón, Leila; Forcelledo, M.L.; Alvarez, Francisco; Massai, Rebeca; Faúndes, Aníbal; Salvatierra, Ana María

doi:10.1016/j.contraception.2004.05.007

Cited by 173 publications

(165 citation statements)

References 29 publications

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“…Mean serum LNG levels on days 1-5 after treatment with the single oral 0.75 mg dose in the Croxatto et al study [12] were between 30 and 60% higher than those observed in the present study after administration of the same dose via CARRA/LNG gel. Furthermore, pharmacokinetic studies indicate that the high peak that occurs 1-2 h after oral administration is missing after the administration of the vaginal gel [10,[14][15][16].…”

Section: Discussioncontrasting

confidence: 75%

“…It is interesting to note that the ability of CARRA/LNG 0.75 mg gel to adversely affect the ovulatory process was at least as effective, or better, than the oral administration of either 0.75 mg or 1.5 mg of LNG (as a single or split dose), previously reported by the same authors [12,13]. The percentage of cycles without follicle rupture was 50% after single oral administration of 0.75 mg and 44% after the standard 0.75 mg × 2 dose, as compared to 74% reported in this study.…”

Section: Discussionsupporting

confidence: 52%

“…The percentage of cycles without follicle rupture was 50% after single oral administration of 0.75 mg and 44% after the standard 0.75 mg × 2 dose, as compared to 74% reported in this study. Similarly, the proportion without follicle rupture or with ovulatory dysfunction was 86% and 79% with the single or standard LNG oral dose as compared with 96% with CARRA/LNG [12]. As the subjects were different in the two studies, a direct comparison may not be valid, but it is at least a strong indication that the expected clinical effectiveness would not be lower, and possibly would be higher, than using the oral route.…”

Section: Discussionmentioning

confidence: 99%

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Effect of mifepristone on endometrial matrix metalloproteinase expression and leukocyte abundance in new medroxyprogesterone acetate users

Felix

Yang

et al. 2007

Contraception

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Objective-The study was conducted to evaluate the effect of Carraguard vaginal gel containing 0.75 mg of levonorgestrel (CARRA/LNG gel) administered in a single dose at different stages of follicle development, over subsequent follicle rupture and hormonal levels.Method-Randomized, blinded, cross-over study comparing the effects of a single administration of CARRA/LNG gel or Carraguard (CARRA) gel. Twenty-four healthy women were enrolled in two centers. The gels were administered when the follicle had reached diameters of 12-14, 15-17 and ≥18 mm in 8 women each. Volunteers were followed for one treatment, one washout cycle and a second treatment cycle. Follicle rupture or non-rupture was assessed by transvaginal ultrasound. LH, estradiol and progesterone levels were measured daily for the 5 days following treatment, and 3 times per week until menses.Results-No follicular rupture within the 5-day period following administration was observed in 74% and 30% of the CARRA/LNG and CARRA gel treatment cycles, respectively, while ovulation was documented in 4% and 61%, respectively. The overall proportion of cycles with lack of follicular rupture or ovulatory dysfunction (follicle rupture preceded by an inadequate LH surge) was 96% for CARRA/LNG and 39% in the CARRA gel cycles.Conclusion-Single vaginal administration of 0.75 mg levonorgestrel in CARRA gel in the late follicular phase, is effective for interfering with the ovulatory process.

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Section: Discussioncontrasting

confidence: 75%

Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 99%

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Effect of mifepristone on endometrial matrix metalloproteinase expression and leukocyte abundance in new medroxyprogesterone acetate users

Felix

Yang

et al. 2007

Contraception

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“…In any event, our results regarding effects on the ovulatory process are within the range of those reported with the use of orally administered LNG in the follicular phase for EC, in which follicular rupture occurred in two thirds of the cycles. Similarly, in that study, half of the follicular ruptures were classified as ovulatory dysfunction based on the blunted or nonexistent LH peak [39]. A study designed to further evaluate the effect of CARRA/LNG on the ovulatory process is currently ongoing.…”

Section: Discussionmentioning

confidence: 99%

Pharmacokinetic study to compare the absorption and tolerability of two doses of levonorgestrel following single vaginal administration of levonorgestrel in Carraguard® gel: a new formulation for “dual protection” contraception

et al. 2007

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Objective: The study was conducted to assess levonorgestrel (LNG) serum levels achieved after a single administration of two different doses of Carraguard vaginal gel containing LNG (CARRA/ LNG), designed for use as microbicide and contraceptive for potential dual-protection. Materials and methods:This was a randomized double-blind pharmacokinetic study conducted in 12 subjects enrolled at two centers. Each subject received a single vaginal administration of CARRA/LNG containing either 0.75 or 1.5 mg LNG per 4 mL of gel on day 10-12 of the menstrual cycle. LNG serum levels were measured at 0, 1, 2, 4, 8 and 12 h after administration and for the following seven days. LH and progesterone (for a preliminary evaluation of effect on the ovarian function) as well as SHBG were measured in the daily samples.Results: Serum LNG maximum concentrations (C max ) were 14.1 ± 5.1 and 11.7 ± 6.5 nmol/L and T max was 12.0 and 6.0 h for the low and high dose, respectively, with large intersubject variability within the first 48 h. Mean levels at 96 h were 10% of C max . Differences in AUC between both doses were not statistically significant. SHBG levels decreased approximately 25% by day 4 after administration. Luteal activity was observed in 3/6 and 5/6 of the subjects in the low and high dose group, respectively. Conclusion:This study demonstrates that the CARRA/LNG gel can sustain elevated serum levels of the contraceptive steroid for up to 96 h after a single application. The serum levels attained with the 0.75 mg formulation are in the range expected to perturb the ovulatory process as observed in some subjects. The lack of correlation between the administered dose and serum concentrations of the steroid may be related to a rate-limiting absorption of LNG from the vaginal mucosa. The results reported here suggest that the CARRA/LNG formulation has good potential to become a dualprotection method, possibly preventing conception and sexually transmitted infections.

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“…LH and P 4 serum levels were determined as described before (Croxatto et al 2004). For both parts of the study, each endometrial sample was divided into two and one piece was flash frozen in liquid nitrogen and stored at K80 8C for subsequent RNA isolation.…”

Section: Methodsmentioning

confidence: 99%

Effect of single post-ovulatory administration of mifepristone (RU486) on transcript profile during the receptive period in human endometrium

et al. 2016

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Progesterone regulates uterine function during the luteal phase and is essential for the acquisition of endometrial receptivity. The objective of the present study was to identify endometrial transcripts whose expression is altered during the window of implantation after the administration of 200 mg of the antiprogestin mifepristone, 48 h after the LH peak (LHC2, LHC0ZLH peak), and to determine the relationship of these transcripts with those regulated during the acquisition of receptivity. Endometrial samples were obtained in LHC7 from seven women of proven fertility, each one contributing with one cycle treated with placebo and another with mifepristone. Additionally, endometrial samples were obtained in LHC2 and LHC7 during a single untreated spontaneous cycle from seven normal fertile women as a reference. DNA microarrays were used to identify transcripts significantly regulated (defined as R2.0-fold change with false discovery rate below 1% using t-test) with the administration of mifepristone vs placebo, or during the transition from pre-receptive to receptive (LHC2 vs LHC7). Approximately 2000 transcripts were significantly regulated in both comparisons (mifepristone vs placebo and LHC2 vs LHC7), but only 777 of them were coincident and displayed opposite regulation except for 25. The mRNA level for eight selected genes regulated by mifepristone was confirmed by real-time RT-PCR. We conclude that not all changes in endometrial transcript levels occurring in the transition from LHC2 to LHC7 seem to be regulated by the progesterone receptor and w37% of the genes whose transcript levels changed by effect of mifepristone could be associated with the acquisition of receptivity.

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Pituitary–ovarian function following the standard levonorgestrel emergency contraceptive dose or a single 0.75-mg dose given on the days preceding ovulation

Cited by 173 publications

References 29 publications

Effect of mifepristone on endometrial matrix metalloproteinase expression and leukocyte abundance in new medroxyprogesterone acetate users

Effect of mifepristone on endometrial matrix metalloproteinase expression and leukocyte abundance in new medroxyprogesterone acetate users

Pharmacokinetic study to compare the absorption and tolerability of two doses of levonorgestrel following single vaginal administration of levonorgestrel in Carraguard® gel: a new formulation for “dual protection” contraception

Effect of single post-ovulatory administration of mifepristone (RU486) on transcript profile during the receptive period in human endometrium

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