RESUMO
OBJECTIVE: The Nestorone/ethinylestradiol (NES/EE) vaginal ring is being developed as a regular contraceptive method by the Population Council. This ring is designed to release NES 150 microg/day and EE 15 microg/day during 1 year. Here, we report a Phase I clinical trial to determine the usefulness of this ring for emergency contraception. To that end, we tested the ability of this ring to interfere with ovulation when it is inserted during the follicular phase. METHOD: Forty-eight women protected from the risk of pregnancy by nonhormonal methods were divided into three groups, which differed by the size of the dominant follicle at the time of ring insertion: 12-14 mm (n = 16), 15-17 mm (n = 18) and >or=18 mm (n = 14) diameter. The NES/EE ring was left in the vagina for 7 consecutive days, after which it was removed. The growth of the leading follicle and plasma levels of estradiol, progesterone (P), luteinizing hormone (LH) and follicle stimulating hormone (FSH) in the ensuing 5 days after ring insertion were determined. Afterwards, steroid hormones were measured twice a week, until menses took place. All women had a control cycle before the ring cycle, and the range of maximum follicular diameter assigned to each volunteer was the same for the control and the ring cycle at the time when placebo was ingested or the ring inserted. RESULTS: During the 5-day period after ring insertion with follicles 12-17 mm, ovulation was absent in 25 of 34 cycles (p < .01 vs. control), and ovulatory dysfunction (absent, blunted or mistimed LH peak) occurred in 8 of the 9 remaining cycles (33/34 ovulatory processes altered; p < .005 vs. control). After ring insertion with follicles >or=18 mm in diameter, ovulation did not occur in 2 of 14 cycles or was dysfunctional in 7 of the 12 remaining cycles (9/14 ovulatory processes altered; p<.025 vs. control). Altogether, 87.5% of ring cycles (42/48) had either no ovulation or ovulatory dysfunction in the 5-day study period, in contrast to 39.6% (19/48 cycles) in control cycles (p < .001). Among follicles that failed to rupture within the 5-day study period, none ruptured later on in the ring-treated cycles, while 9 of 16 did so in control cycles. Sixty-two percent of ring-treated cycles were shorter than 24 days. Nausea, vaginal discharge and abdominal pain were the most frequently reported adverse events during ring use. CONCLUSION: Interference with 87.5% of ovulatory processes, without ovulation occurring later in the cycle and shortening of cycle length, suggests the NES/EE ring may be used as an emergency contraceptive method, with the potential advantage of providing continuing contraception after it has performed its emergency function.
Assuntos
Anticoncepção Pós-Coito/métodos , Etinilestradiol/administração & dosagem , Norprogesteronas/administração & dosagem , Administração Intravaginal , Adulto , Estradiol/sangue , Etinilestradiol/efeitos adversos , Etinilestradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hormônio Luteinizante/sangue , Ciclo Menstrual , Norprogesteronas/efeitos adversos , Norprogesteronas/sangue , Folículo Ovariano/diagnóstico por imagem , Ovulação , Progesterona/sangue , Ultrassonografia , Hemorragia Uterina/epidemiologiaRESUMO
Contraceptive vaginal rings delivering various progestins alone or in combination with estrogen have been previously studied, showing adequate steroid vaginal absorption and acceptability by the users. Nestorone progestin (NES) is a potent 19-nor-progesterone derivative, inactive by the oral route, but an excellent option for vaginal delivery. The purpose of this study was to evaluate ovarian function during 6 months of continuous use of progestin-only vaginal rings delivering 3 different doses of NES: 50, 75, and 100 microg per day. Blood samples were taken twice a week for 5 consecutive weeks during a control cycle and on months 1, 3 and 6 of use, for the measurement of estradiol (E2), progesterone (P), and NES. A total of 87 volunteers randomly received each of the 3 doses. After an initial peak, NES serum levels remained fairly constant throughout the duration of the study at about 125, 200 and 250 pmol/L, respectively, decreasing slightly with time. Luteal activity occurred very rarely (1.2-2.6% of sampling periods) with no apparent difference between doses. Low E2 levels (< or =100 pmol/L) in all samples of a run were rare (5%) and only with the high dose ring (100 microg/day). E2 remained within normal levels (101-1500 pmol/L) in most of the segments studied. We conclude that the 50 and 75 microg/day NES rings provide adequate ovulation inhibition without hypoestrogenism, while the 100 microg/day ring may deliver an unnecessarily high dose.
Assuntos
Anticoncepcionais Femininos/administração & dosagem , Dispositivos Anticoncepcionais Femininos , Norprogesteronas/administração & dosagem , Ovário/efeitos dos fármacos , Administração Intravaginal , Adolescente , Adulto , Anticoncepcionais Femininos/sangue , Implantes de Medicamento , Estradiol/sangue , Estradiol/metabolismo , Feminino , Humanos , Norprogesteronas/sangue , Ovário/metabolismo , Ovário/fisiologia , Progesterona/sangue , Progesterona/metabolismoRESUMO
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.
Assuntos
Anticoncepcionais Femininos/administração & dosagem , Norprogesteronas/administração & dosagem , Ovário/efeitos dos fármacos , Ovário/fisiologia , Adolescente , Adulto , Anticoncepcionais Femininos/sangue , Relação Dose-Resposta a Droga , Implantes de Medicamento , Estradiol/sangue , Feminino , Humanos , Norprogesteronas/sangue , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/fisiologia , Ovário/diagnóstico por imagem , Ovulação/efeitos dos fármacos , Progesterona/sangue , UltrassonografiaRESUMO
The clinical performance and the in vivo release rate of a single 4-cm Nestorone subdermal implant were investigated. Implants manufactured by two different procedures were compared. Volunteers were 70 healthy women of proven fertility. Forty women provided blood samples twice a week in the pretreatment cycle and for 5-6 weeks at 6-month intervals during treatment. Additional control cycles (n = 31) were studied in 19 Copper T users. No pregnancy occurred in 1570 woman-months. Nestorone plasma levels (x +/- S.E.) declined from 112 +/- 8 to 86 +/- 3 pmol/L (Implant A) and from 145 +/- 8 to 57 +/- 5 pmol/L (Implant B) from the first to the 24th month. Progesterone levels were < 9.5 nmol/L in 166 (93%) of 178 blood samplings taken during treatment. Progesterone levels > 16 nmol/L were found in only 7 sampling periods (3.9%) in treated women and in 70 (98.6%) out of 71 control cycles. No ovulation occurred with Nestorone plasma levels above 105 pmol/L. No abnormal changes were observed in plasma lipoproteins or other clinical chemistry parameters during treatment. The implants were well tolerated. The most frequent complaint was the occurrence of irregular bleeding. Enlarged follicles found during pelvic examination in 8 subjects (11.4%) disappeared spontaneously in 10 days to 6 weeks. Implants were removed because of medical (n = 10, 14.3%) or personal reasons (n = 6, 8.6%) or at the 24th month of treatment (n = 54, 77.1%). The estimated average daily in vivo release rate of Nestorone was 45-50 micrograms/day. A single Nestorone subdermal implant affords efficient contraceptive protection during two years.
Assuntos
Anticoncepcionais Femininos/administração & dosagem , Anticoncepcionais Femininos/normas , Norprogesteronas/administração & dosagem , Norprogesteronas/normas , Adolescente , Adulto , Anticoncepcionais Femininos/sangue , Implantes de Medicamento , Feminino , Humanos , Ciclo Menstrual/fisiologia , Norprogesteronas/sangue , Ovário/fisiologia , Progesterona/sangueRESUMO
Four different models of contraceptive vaginal rings were tested during three cycles for luteal activity, bleeding control, plasma lipoproteins and serum levels of the contraceptive steroids. Two progestins, levonorgestrel acetate (LNGA) and ST 1435, alone or in combination with ethynyl-estradiol (EE) were tested. The rings released 100 ug/day of the progestins and 30 ug/day of EE. Luteal activity was detected among users of the progestin-only rings: 4 of 8 cycles with ST 1435 and 2 of 10 with LNGA. Only one of the 18 cycles studied with the two combined rings showed luteal activity, but the measurement of contraceptive steroid in plasma suggested that this subject delayed reinsertion of the ring for about one week in that particular cycle. Breakthrough bleeding was observed in 12 of 30 cycles of use of the progestin-only rings, and in only 2 of 27 cycles with the combined models. No significant changes in total cholesterol or its HDL-fraction were observed. However, the only reduction observed in HDL-cholesterol was among users of the LNGA-only ring. It is concluded that the two combined CVR models offer good possibilities of high effectiveness and bleeding control and merit further development.
PIP: Researchers analyzed data on 20 18-38 year old volunteers from the family planning clinic of PROFAMILIA in Santo Domingo, Dominican Republic, who had earlier undergone female sterilization to evaluate 4 different models of contraceptive vaginal rings during 3 cycles so as to identify which models would be the most likely to be an acceptable, safe, and effective family planning method. Women who used either of the 2 combined rings (ethinyl estradiol [EE] and either levonorgestrel acetate [LNGA] or ST 1435) had higher mean total serum levonorgestrel levels than those using the progestin-only rings (LNGA or ST 1435) (most were significant at .005). Luteal activity which marked ovulation was basically limited to users of the progestin-only rings (50% of cycles with ST 1435 and 20% of LNGA). It occurred in 1 of 18 cycles (5.6%) of users of combined rings (LNGA + EE). It probably occurred because of delayed insertion. The combined rings caused fewer incidents of breakthrough bleeding than did the progestin-only rings (7.4% vs. 40%). Neither the progestin-only nor the combined vaginal rings significantly altered total cholesterol or high density lipoprotein (HDL) levels. Users of the LNGA-only ring did experience an insignificant reduction in HDL, however. Further, triglycerides increased among users of the combined vaginal rings, but the increase was only significant with the LNGA + EE ring (25.4 mg/dl increase; p .05). Moreover, they fell significantly among users of the LNGA only ring (45.5 mg/dl decrease; p .05). The researchers concluded that the 2 combined rings hold the most promise due to good bleeding control and high effectiveness and therefore deserve further development.