The effect of extending the pill-free interval on follicular activity: triphasic norgestimate/35 micro g ethinyl estradiol versus monophasic levonorgestrel/20 micro g ethinyl estradiol

This study was designed to evaluate follicular activity in women taking oral contraceptives with imposed imperfect compliance. After completing a 28-day cycle of either triphasic norgestimate/EE (NGM/EE) (Ortho Tri-Cyclen, Ortho-McNeil Pharmaceutical, Raritan, NJ) or monophasic levonorgestrel/EE (LNG/EE) (Alesse, Wyeth-Ayerst Laboratories, Philadelphia, PA), women were instructed to intentionally "miss" the first two active pills of the next pack. The first two tablets in the second treatment cycle were deliberately omitted, thereby extending the pill-free interval from 7 days to 9 days. Subjects were randomized to take NGM/EE (n = 40) or LNG/EE (n = 39) for two consecutive cycles. The mean maximum follicular diameter was significantly greater in women taking LNG/EE than in those taking NGM/EE (16.4 +/- 7.1 mm vs. 12.6 +/- 8.3 mm, p = 0.047). The LNG/EE group had significantly higher median serum estradiol concentrations compared to women taking NGM/EE on pill Days 10 [29.5 pg/mL (range: 10.0-540.0 pg/mL) vs. 2.5 pg/mL (range: 2.0-6.0 pg/mL), p < 0.001] and 14 [11.0 pg/mL (range: 2.0-416.0 pg/mL) vs. 2.0 pg/mL (range: 2.0-3.0 pg/mL), p = 0.001]. Two women in the NGM/EE group and three women in the LNG/EE group had at least one progesterone level > or =3 ng/mL; none of these women demonstrated a maximum follicular diameter >13 mm. Significantly greater follicular activity was observed after an extended pill-free interval in women taking LNG/EE compared to those taking triphasic NGM/EE. The clinical implications of these findings require further study.     

Ethinyl estradiol and levonorgestrel pharmacokinetics with a low-dose transdermal contraceptive delivery system, AG200-15: a randomized controlled trial

BackgroundThis study evaluated the ethinyl estradiol (EE) and levonorgestrel (LNG) pharmacokinetic profiles of AG200-15, a transdermal contraceptive delivery system, compared with a combination oral contraceptive (COC) containing EE 35 mcg and norgestimate 250 mcg.Study designA Phase 1, open-label, single-center study in 36 healthy women was conducted over three cycles with a randomized crossover design. After a run-in cycle of 21 days on and 7 days off with AG200-15, participants were randomized to receive one of two treatments: a 21/7-day cycle of AG200-15 either followed or preceded by one cycle of the COC. This trial is registered on ClinicalTrials.gov under the identifier NCT01243580.ResultsDuring the third week of AG200-15 use, mean (±standard deviation) maximum serum concentration (C_max), area under the curve_{0–168 h} and steady-state concentration (C_{ss48–168 h}) for EE were 51.3±17.3 pg/mL, 6.26±2.46 ng h/mL and 35.7±14.5 pg/mL, respectively; for LNG, the corresponding values were 2400±1140 pg/mL, 317±159 ng h/mL and 1847±930 pg/mL, respectively. The AG200-15 EE C_max was approximately 60% lower and the EE C_ss was 15%–20% lower than those obtained with the COC. The calculated daily dose of AG200-15 was equivalent to a 30-mcg EE COC. The most common adverse events (AEs; >10%) in the AG200-15 group were headache, nausea and application-site irritation. All drug-related AEs were mild, and no serious AEs were reported.ConclusionsEE and LNG daily exposure during AG200-15 treatment was within the range reported for a low-dose COC. The daily EE dose with AG 200-15 was equivalent to a 30-mcg COC and was safe and well tolerated.     

聚三亚甲基碳酸酯-丙交酯共聚物微球长效避孕体系的研究

目的:用可生物降解共聚物聚三亚甲基碳酸酯-丙交酯(PTMC-co-DL-LA)为载体,制备含左旋18甲基炔诺酮(LNG)的载药微球,初步考察不同共聚组成聚合物制得的微球性能及体外释放行为,探讨该共聚物微球作为LNG的长效避孕释放载体的可行性。方法:采用溶剂挥发法(O/W),用不同共聚组成比的PTMC-co-DL-LA及其相应均聚物聚三亚甲基碳酸酯(PTMC)和聚丙交酯(PDLLA)制备含LNG的可生物降解微球,表征制得微球的粒径大小及分布、表面形态等性能,考察不同共聚组成聚合物微球对LNG的体外释放行为。结果:粒径均匀分布较窄,平均粒径<5μm:含LNG的微球表面平整光滑,其包封率均>90%。共聚物微球的LNG释放速率均较PTMC和PDLLA均聚物低,体现出良好的长效释放行为。结论:不同共聚组成聚合物制得的微球LNG的释放速率不同,均具有对LNG的长效释放作用,有望通过体内研究,使载有LNG的PTMC-co-DL-LA共聚物微球用于长效避孕。     

A biodegradable levonorgestrel-releasing implant made of PCL/F68 compound as tested in rats and dogs

PURPOSE: Our objective was to report preclinical studies on a biodegradable long-acting contraceptive implant. METHODS: A poly (epsilon-caprolactone) (PCL)/pluronic F68 (F68) compound was used to construct an implant, which was filled with dry levonorgestrel (LNG) powder (PCL/F68/LNG). LNG release rate, contraceptive efficacy and polymer degradation were evaluated in rats and followed for 2 years. A 2-year toxicity study was conducted in dogs. RESULTS: The in vitro and in vivo release of LNG from the implant followed zero-order release kinetics. Serum LNG level in rats was very stable during the 2-year period. Studies on polymer degradation indicated that the molecular weight of PCL dropped from 66,000 to 15,000 Da, but the implant was still in good shape by the end of 2 years. CONCLUSION: Toxicological study demonstrated that the PCL/F68 polymer had no adverse effect in all aspects. The contraceptive efficacy in rats showed dose response. The implant was physically and chemically stable for up to 3 years in airproof aluminum foil packing at room temperature.     

Quantitative levonorgestrel plasma level measurements in patients with regular and prolonged use of the levonorgestrel-releasing intrauterine system

BackgroundThe levonorgestrel-releasing intrauterine system (LNG-IUS) is well accepted as an easy-to-use contraceptive with an excellent side-effect profile. It contains a reservoir of 52 mg of levonorgestrel (LNG) with continuous release of the steroid. Its contraceptive use is approved for 5 years. The aim of this study was to determine the plasma concentration of LNG and its variation with time in patients with in-dwelling LNG-IUS Mirena®.Study DesignIn this study, we determined LNG plasma concentrations in 110 women with LNG-IUS at different time points of use. Time from insertion of the system in the study population ranged from 20 days to 11.1 years. Quantitative LNG levels were determined using a validated liquid chromatography–tandem mass spectrometry assay.ResultsThe mean±SD LNG plasma level in all women was 147±59 pg/mL. A highly significant negative correlation between LNG plasma level and LNG-IUS time of use could be demonstrated. In the first year of use, LNG plasma level was as high as 191±71 pg/mL, decreasing to 157±68 pg/mL in the second year and 134±41 pg/mL in the third year. Even after exceeding the recommended period of LNG-IUS use, systemic LNG concentrations were detectable: 133±38 pg/mL in the sixth year, 133±48 pg/mL in the seventh year and 117±45 pg/mL in the eighth year. Furthermore, a significant negative correlation between LNG plasma level and body mass index could be shown.ConclusionSystemic LNG concentrations can be found in all patients with LNG-IUS IUS. However, concentrations are much lower than in other forms of LNG application. Moreover, this study demonstrates that a systemic effect of LNG-IUS can also be found after the recommended contraceptive lifespan of 5 years.     

Pharmacokinetics of oral contraceptive steroids in Egyptian women: studies with Ovral, Nordette and Norminest

Plasma concentration profiles and pharmacokinetic parameters have been obtained following single dose administration of three commonly used oral contraceptive steroid preparations, Ovral, Nordette and Norminest to Egyptian women. The constituents of the preparations are as follows: Ovral (50 micrograms ethinyloestradiol, EE2 and 500 micrograms levonorgestrel, LNG); Nordette (30 micrograms EE2 and 150 micrograms LNG); and Norminest (35 micrograms EE2 and 500 micrograms norethisterone, NOR). Peak plasma concentrations of EE2 ranged between 116-160 pg ml-1 for Ovral, 55-78 pg ml-1 for Norminest and 30-70 pg ml-1 for Nordette. There was no significant difference in half-life (t1/2), oral clearance (CL) or apparent volume of distribution (Vd). The relative values of the area under the plasma concentration-time curve (AUC) reflected well the different amounts of oestrogen in each preparation. There was no significant difference in t1/2, CL or Vd for LNG in the 2 preparations containing this progestogen. The mean AUC following Nordette (150 micrograms LNG) was 40% of that following Ovral (500 micrograms LNG; p less than 0.001). Comparing pharmacokinetic parameters for the same dose of LNG (Ovral) and NOR (Norminest) showed the AUC to be decreased and CL and Vd increased in the latter group. The study indicates that the kinetic profile of the OCS in healthy Egyptian women are similar to other ethnic populations.     

Effects of transdermal and oral contraceptives on estrogen-sensitive hepatic proteins

OBJECTIVE: The purpose of this study was to evaluate the effects of the contraceptive patch and an oral contraceptive (OC) on serum concentrations of estrogen-sensitive hepatic proteins, ethinyl estradiol (EE) and levonorgestrel (LNG). METHODS: Twenty-four women were randomized to receive three cycles of a contraceptive patch that delivers EE 20 microg/day and norelgestromin 150 microg/day or an OC that contains EE 35 microg and norgestimate 250 microg. Blood samples were taken at baseline and at the end of Cycle 3. Serum levels of sex-hormone-binding globulin (SHBG), thyroxine-binding globulin (TBG), corticosteroid-binding globulin (CBG) and C-reactive protein (CRP) were quantified by immunoassay methods. EE and LNG levels in patch users were measured by radioimmunoassay (RIA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The paired t test and Student's t test were used for statistical analysis. RESULTS: Nineteen women completed the study (patch, n=10; OC, n=9). Treatment with both the patch and OC resulted in significant increases from baseline in SHBG, TBG and CBG. The increase in CRP was significant in the patch group and approached significance in the OC group. The increases in SHBG and TBG observed with the patch were significantly greater than those associated with the OC. By way of RIA and LC-MS/MS assay methods, the patch was associated with mean EE levels of 114 and 111 pg/mL, respectively. CONCLUSIONS: The serum concentrations of estrogen-sensitive hepatic proteins and EE associated with the patch suggest that this new contraceptive system may have relatively large net estrogen effects.     

Pharmacokinetic comparison of two triphasic oral contraceptive formulations containing levonorgestrel and ethinylestradiol

The pharmacokinetics of levonorgestrel (LNG) and ethinylestradiol (EE2) were determined in 24 women (aged 21 to 35 years), following the administration of a single tablet from the second phase of two different triphasic preparations (Triphasil and Trinordiol. Each tablet contained 0.075 mg of LNG and 0.040 mg of EE2. The data were compared to the pharmacokinetics of LNG and EE2 obtained following the oral administration of a hydroalcoholic solution (standard) containing the same steroids and dose. The study consisted of a randomized design in which the three formulations were administered to each of the 24 subjects in a three-period crossover pattern. Blood samples were taken at frequent intervals after dosing. Serum levels of LNG and EE2 were measured by specific radioimmunoassays. The results show that both LNG and EE2 in the Triphasil and Trinordiol tablets are bioequivalent with respect to rate and extent of absorption. Furthermore, LNG, but not EE2, in both tablet formulations was bioequivalent to the solution dose. The serum concentration-time profiles for the three formulations showed that the range of mean peak levels was 2.3-2.8 ng/ml for LNG and 116-159 pg/ml for EE2. These levels were achieved within 2 hours in the majority of subjects. The ranges of mean values calculated for the areas under the curves were 15-16 ng.hr/ml for LNG and 1053-1390 pg.hr/ml for EE2. The ranges of mean values calculated for other pharmacokinetic parameters were: volume of distribution: LNG--1.6-1.8 L/kg, EE2--7.7-9.1 L/kg; clearance: LNG--84-88 ml/hr/kg, EE2--0.67-0.99 ml/hr/kg; half-life: LNG--13-15 hr, EE2--7-12 hrs.     

PCT、TREM-1联合CPIS评分对新生儿呼吸机相关性肺炎的早期诊断价值研究

目的 探讨降钙素原(PCT)、髓系细胞表达的触发受体-1(TREM-1)联合肺部感染评分(CPIS)评分对新生儿呼吸机相关性肺炎(VAP)早期诊断的临床价值.方法 以88例有创机械通气患儿作为研究对象,所有患儿均在机械通气后第1天、第3天、第7天采集外周血及肺泡灌洗液标本并进行检测,同时进行CPIS评分,根据治疗后评估,将88例患儿分为VAP组(46例)与非VAP组(42例),应用ROC曲线评价PCT、TREM-1、CPIS联合指标对VAP的早期诊断价值.结果 两组的PCT(第1天:0.53±0.15ng/mL vs 0.36±0.12ng/mL;第3天:2.07±1.22ng/mL vs 0.45±0.13ng/mL;第7天:2.54±1.31ng/mL vs 0.47±0.12ng/mL)、TREM-1(第1天:4.18±1.17pg/mL vs 3.01±0.78pg/mL;第3天:3.01±0.78pg/mL vs 3.52±0.85pg/mL;第7天:9.62±1.93pg/mL vs 4.03±1.14pg/mL)、CPIS评分(第1天:4.2±1.1分vs 3.4±1.2分;第3天:5.2±0.9分vs 3.3±1.1分;第7天:5.5±1.2分vs 3.6±1.4分)差异有统计学意义(PCT:t值分别为-5.369、-7.583、-9.034;TREM-1:t值分别为-4.985、-7.370、-14.834;CPIS评分:t值分别为-3.053、-8.381、-6.437;均P<0.01).第3天指标的诊断效能最高,PCT、TREM-1、CPIS评分联合指标对诊断VAP的敏感性、特异性、阳性预测值、阴性预测值分别80.4%、100.0%、93.5%、100.0%.结论 结合PCT、TREM-1、CPIS评分综合分析,可以显著提高诊断的特异性,对新生儿VAP的早期诊断有较好的实用性.     

Progesterone release from glutaraldehyde cross-linked casein microspheres: in vitro studies and in vivo response in rabbits

Microspheres of bovine milk protein casein loaded with progesterone were fabricated by glutaraldehyde cross-linking of an aqueous alkaline solution of the protein dispersed in a hexane and dichloromethane non-aqueous dispersion medium with an aliphatic polyurethane as the stabilizer. Microspheres were characterized for their surface morphology and internal structure using scanning electron microscopy. In vitro release studies in phosphate buffer at 37 degrees C demonstrated that the rate of release of the steroid from the microsphere matrix was a function of cross-linking density, particle size, and drug payload. Microsphere formulations released 50% to 60% of the incorporated steroid in about 30 days and, thereafter, attained a steady state. In the presence of a protein-digesting enzyme such as protease, complete release of the steroid was observed in about 4 days in vitro into phosphate buffer. Intramuscular injection of progesterone-loaded microspheres into rabbits showed a plasma concentration of 1 to 2 ng/mL up to 5 months without any significant burst effect, whereas the powdered steroid administered in saline demonstrated a large burst effect peaking over 20 ng/mL, and the plasma concentration was not sustained beyond 4 days. Data obtained suggest that casein microspheres would be promising as a biodegradable drug carrier for sustained delivery of steroids.     

Pharmacokinetics of a combined oral contraceptive in obese and normal-weight women

Background

This study was conducted to compare oral contraceptive (OC) pharmacokinetics (PK) in normal-weight [body mass index (BMI) 19.0–24.9] and obese (BMI 30.0–39.9) women.

Study Design

During the third week of the third cycle of OC use, we admitted 15 normal-weight and 15 obese women for collection of 12 venous specimens over 24 h. Using radioimmunoassay techniques, we measured levels of ethinyl estradiol (EE) and levonorgestrel (LNG). During the same cycle, women underwent twice-weekly sonography to assess ovarian follicular development and blood draws to measure endogenous estradiol (E2) and progesterone levels.

Results

Obese women had a lower area under the curve (AUC; 1077.2 vs. 1413.7 pg?h/mL) and lower maximum values (85.7 vs. 129.5 pg/mL) for EE than normal-weight women (p=.04 and <0.01, respectively); EE trough levels were similar between BMI groups. The similar, but smaller, differences in their LNG levels for AUC and maximum values (C_max) were not statistically significant. While peak values differed somewhat, the LNG trough levels were similar for obese and normal-weight women (2.6 and 2.5 ng/mL, respectively). Women with greater EE AUC had smaller follicular diameters (p=.05) and lower E2 levels (p=.04). While follicular diameters tended to be larger among obese women, these differences were not statistically significant.

Conclusion

OC hormone peak levels are lower among obese women compared to normal-weight women, but their trough levels are similar. In this small study, the observed PK differences did not translate into more ovarian follicular activity among obese OC users.     

Therapeutically equivalent pharmacokinetic profile across three application sites for AG200-15, a novel low-estrogen dose contraceptive patch

BackgroundAG200-15 Agile Patch (AP) is a novel 7-day contraceptive patch providing ethinyl estradiol (EE) exposure comparable to low-dose combination oral contraceptives. This study determined whether application of the AP to three different anatomical sites (lower abdomen, buttock and upper torso) influences the pharmacokinetic profile of EE and levonorgestrel (LNG).Study DesignIn this open-label, three-period, crossover study, 24 subjects were randomized to one of six treatment sequences; each included application of patch to abdomen, buttock and upper torso, with the AP worn on one site for 7 days. After a 7-day washout, a new patch was applied to the next anatomical site. Multiple blood samples were collected up to 240 h after patch application.ResultsFor plasma EE levels, median time to maximum drug concentration (T_max, 24–48 h) and mean maximum concentration (C_max, 47.9–61.5 pg/mL) were similar among application sites. Compared with lower abdomen, EE exposure was higher (16%–30%) at buttock and upper torso (15%–22%). For plasma LNG levels, median T_max (72–120 h) and mean C_max (1436–1589 pg/mL) were similar across application sites. Compared with lower abdomen, LNG exposure was higher at buttock (1%–7%) and upper torso (16%–17%). No serious adverse events (AEs) or AE-related discontinuations occurred. The most common treatment-emergent AEs were nausea, application site pruritus and headache, with frequencies comparable across anatomical sites.ConclusionsAbsorption from the abdomen was slightly lower versus other sites; however, exposure to EE and LNG for all sites was therapeutically equivalent. The AP was well tolerated at all three anatomical sites.     

A 1-year randomized study to evaluate the effects of a dose reduction in oral contraceptives on lipids and carbohydrate metabolism: 20 microg ethinyl estradiol combined with 100 microg levonorgestrel

OBJECTIVES: To evaluate the impact on lipid and carbohydrate variables of a combined one-third ethinyl estradiol (EE)/levonorgestrel (LNG) dose reduction in oral contraceptives. METHODS: In an open-label, randomized study, a dose-reduced oral contraceptive containing 20 microg EE and 100 microg LNG (20 EE/100 LNG) was compared with a reference preparation containing 30 microg EE and 150 microg LNG (30 EE/150 LNG). One-year data from 48 volunteers were obtained. RESULTS: We found a decrease of HDL2 cholesterol and increases of low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and total triglycerides in both treatment groups from baseline to the 13th treatment cycle. Although for four of six variables, the changes in the 20 EE group were lower compared with the 30 EE group, none of the differences between the two treatments were statistically significant. The median values for the fasting levels of insulin, C-peptide and free fatty acids slightly increased or remained unchanged while the fasting glucose levels slightly decreased after 13 treatment cycles. While the glucose area under the curve (AUC) (0-3 h) was similar in both groups during the OGTT, the insulin AUC(0-3 h) was less increased in the 20 EE/100 LNG group compared with the 30 EE/150 LNG group. None of the differences between the treatment groups for any of the carbohydrate metabolism variables were statistically significant at any time point. Both study treatments were safe and well tolerated by the volunteers. CONCLUSION: Similar effects on the lipid and carbohydrate profiles were found for both preparations. The balanced one-third EE dose reduction in this new oral contraceptive caused slightly lower, but insignificant, changes in the lipid and carbohydrate variables compared with the reference treatment.     

Multicenter, comparative study of cycle control, efficacy and tolerability of two low-dose oral contraceptives containing 20 microg ethinylestradiol/100 microg levonorgestrel and 20 microg ethinylestradiol/500 microg norethisterone

A comparison of cycle control, efficacy and tolerability of two oral contraceptive preparations containing 20 microg ethinylestradiol combined with either 100 microg levonorgestrel (EE/LNG 20/100) or 500 microg norethisterone (EE/NET 20/500) was conducted. These results were compared to a standard reference preparation, containing 30 microg ethinylestradiol combined with 150 microg levonorgestrel (EE/LNG 30/150). Efficacy data from 8,544 treatment cycles were obtained from 767 women. Good cycle control and effective contraception was achieved with the two LNG preparations, however, the cycle control results were less favorable with EE/NET 20/500. The cumulative incidence of women with at least one episode of intermenstrual bleeding from cycles 2 to 7 (primary target variable) was 43.9% for EE/LNG 20/100, 72.7% for EE/NET 20/500, and 15.7% for the standard EE/LNG 30/150. The difference between the 2 20 microg of EE preparations, which favored EE/LNG 20/100, was statistically significant (p = 0.001). The overall spotting rates (cycles 1-13) were 9.3% for EE/LNG 20/100, 21.7% for EE/NET 20/500, and 3.3% for the standard EE/LNG 30/150. Amenorrhea was reported in 7.1% (EE/LNG 20/100), 20.6% (EE/NET 20/500), and 0.9% (standard EE/LNG 30/150), respectively. Intermenstrual bleeding episodes were shorter with EE/LNG 20/100 and EE/LNG 30/150 of the 13 treatment cycles. The study Pearl indices were 0.9 for EE/LNG 20/100, 1.9 for EE/NET 20/500, and 0.0 for EE/LNG 30/150. All three treatments were well tolerated. However, tolerability was somewhat less favorable with EE/NET 20/500. A total of 160 women prematurely discontinued the study for various reasons (EE/LNG 20/100: 7%; EE/NET 20/500: 18%; EE/LNG 30/150: 4%). The overall adverse event incidence rate during the trial was low in all groups. Blood pressure remained largely unaffected. Thirteen serious adverse events were recorded for all treatment groups, all but one were assessed as not related to the treatments. There were no remarkable treatment related differences in mean body weight throughout the study and the laboratory values were largely unaffected in all three treatments groups.     

Phase I comparative clinical trial with subdermal implants--bioabsorbable levonorgestrel or norethisterone pellet fused with cholesterol

The potential for antifertility effect of two bioabsorable pellets, one containing norethisterone (NET) and the other containing levonorgestrel (LNG) fused with cholesterol, was studied in a group of healthy, menstruating but sterilised women. The pellets weighed approximately 30 mg and contain 85% steroid and 15% cholesterol. A single NET pellet was inserted in 4 subjects, out of which 2 were also studied for steroid pattern in blood. After reaching peak levels within 48 hours, the plasma NET levels declined gradually within a fortnight's time, and thereafter, ranged between 200 to 700 mg/ml up to 90 days post-insertion. After this period, occassional spurts of NET release were seen. Bleeding pattern was studied in 37 cycles; mid-luteal progesterone (P) estimation was done in 16 cycles, mid-cycle cervical mucus was studied in 27 cycles and post-coital test (PCT) in 7 cycles. Cycle length with pellet insertion was of 25 to 37 days duration except one cycle of 55 days duration. All cycles studied during the treatment were ovulatory (P greater than 5 ng/ml) and no consistent effect was observed on cervical mucus as well as on PCT. Thus, a single NET pellet does not seem to have a reliable contraceptive potential. A single LNG pellet was inserted in 8 subjects, and steroid patterns were studied in 6 women. Peak levels of LNG were reached within 24 hours of pellet insertion and the levels fell gradually in a week's time. Thereafter, LNG levels ranged between 100-400 pg/ml up to 8 months. In contrast to the observation with NET pellets, only one subject showed frequent spurts of LNG release until the 4th month of treatment. Bleeding pattern was studied in 90 cycles, P was estimated in 52 cycles, mid-cycle cervical mucus studied in 55 cycles and PCT done in 26 cycles. Breakthrough bleeding (BTB) occurred on 15 occasions, 11 episodes being in 2 subjects. Cycle length varied between 21 to 42 days. The LNG pellet did not exert a consistent effect either on ovulation inhibition or cervical mucus or PCT. In their present form, therefore, a single LNG pellet also does not appear to have a reliable contraceptive effect.     

Pharmacokinetics of levonorgestrel and ethinylestradiol in 9 women who received a low-dose oral contraceptive over a treatment period of 3 months and, after a wash-out phase, a single oral administration of the same contraceptive formulation.

The pharmacokinetics of levonorgestrel (LNG) and ethinylestradiol (EE2) were determined in 9 healthy women (age 23 to 42 years), during a treatment period of three months with a low-dose oral contraceptive, containing 0.15 mg LNG together with 0.03 mg EE2 (Microgynon). After a wash-out period of 3 months, 8 of these women received a single administration of the same formulation. The results showed that there was an increase in serum trough levels of LNG, reaching steady-state in the second half of each treatment cycle. The LNG levels achieved were about 3 to 4 times higher than anticipated on the basis of single dose administration. At the end of treatment cycles one and three, the terminal half-life of LNG was in the range of 24-26 h, while a mean value of 20 h was observed following single dose administration. An EE2-induced increase in the SHBG concentration of about 50% as compared to pretreatment values was observed during a treatment cycle. Pretreatment values were reached following the drug-free interval of 7 days between two cycles. After single dose administration, the free fraction of LNG was 1.3 +/- 0.2% and the fractions bound to SHBG and albumin were 64.1 +/- 4.2% and 34.6 +/- 4.0%, respectively. Serum protein binding of LNG did not change during chronic treatment. An about 50% reduction in total and unbound clearance of LNG was observed during chronic treatment, as compared to single dose administration. Increased SHBG binding capacity and a reduced hepatic metabolic capacity were discussed as possible causes of accumulating LNG concentrations in the serum. On the last day of treatment cycles one and three, the AUC(0-24h) values of EE2 were 728 +/- 314 and 778 +/- 318 pg x ml-1 x h, respectively, and were in keeping with data reported from others.     

The contraceptive vaginal ring (NuvaRing) and hemostasis: a comparative study

This open-label, nonrandomized study compared changes in hemostatic variables during NuvaRing® and oral levonorgestrel 150 μg/ethinylestradiol 30 μg (LNG/EE) use for six cycles. Eighty-seven women started the study, 44 with NuvaRing and 43 with the LNG/EE oral contraceptive. For most procoagulation variables, there was no difference between NuvaRing and oral LNG/EE; only Factor VII levels increased in the NuvaRing group and decreased in the LNG/EE group. The majority of assessed variables show that anticoagulation and fibrinolytic activity was comparable between the NuvaRing and oral LNG/EE groups. Antithrombin activity and protein C activity both tended to be higher with NuvaRing. Levels of tissue plasminogen activator decreased in both groups but the reduction was smaller with NuvaRing. There were no significant differences in fibrin turnover between the treatment groups. The data show that both NuvaRing and oral LNG/EE are associated with a minimal effect on hemostatic variables.     

Endometrial effects of a 91-day extended-regimen oral contraceptive with low-dose estrogen in place of placebo

BACKGROUND: The study was conducted to evaluate the effects of a 91-day extended-regimen oral contraceptive (OC) containing levonorgestrel (LNG) with low-dose ethinyl estradiol (EE) in place of placebo on endometrial histology. STUDY DESIGN: Endometrial biopsies were obtained prior to initiation and posttreatment, between cycle Days 60 and 84 (during combination EE/LNG tablets), between cycle Days 85 and 91 (during low-dose EE tablets) or after completion of therapy. RESULTS: Paired endometrial biopsy samples obtained before and after treatment were available for 63 subjects. Biopsy results demonstrated that this OC regimen did not promote unexpected changes in the endometrium, either during the course of active treatment with EE/LNG or during the 7-day low-dose EE interval. Endometrial hyperplasia or malignancy was not observed in any endometrial biopsy sample. CONCLUSION: Use of a 91-day extended-regimen OC with low-dose EE in place of placebo was not associated with any untoward effects on the endometrium.     

Effects of two combined hormonal contraceptives with the same composition and different doses on female sexual function and plasma androgen levels

Background

This study was conducted to compare the effects of two contraceptive pills with different doses of the same components, on plasma androgen levels and female sexual function among women without previous sexual dysfunction.

Study Design

The participants were randomized into two groups, to receive pills containing ethynylestradiol (EE) 30 mcg and levonorgestrel (LNG) 150 mcg or EE 20 mcg and LNG 100 mcg, for six cycles. Sexual function was assessed using a standardized questionnaire [Female Sexual Function Index (FSFI)]. Hormone assays were performed at baseline and after the sixth cycle.

Results

Forty-nine women were included in the EE30/LNG150 group and 48 in the EE20/LNG100 group. EE30/LNG150 group presented 54% and 67% decreases of total testosterone and free androgen index, respectively, with statistical significance. EE20/LNG100 presented reductions of 20% and 42%, respectively, but without statistical significance. Both groups showed improvements in the FSFI “desire” score, but with statistical significance only for EE20/LNG100 group.

Conclusions

EE30/LNG150 decreased plasma androgen levels, but there was no impairment in sexual desire, on the other hand, sexual desire score increased with EE20/LNG100 formulation.     

Timing of onset of contraceptive effectiveness in Norplant implant users. II. Effect on the ovarian function in the first cycle of use.

The objective of this study was to time the onset of contraceptive effectiveness in Norplant implant users, when the capsules were inserted beyond the first 7 days of the cycle, based on the immediate effect on the ovarian activity. A total of 42 healthy women requesting Norplant implant contraception were enrolled at clinics in Santo Domingo, Dominican Republic, and in Baltimore, Maryland. Implants were inserted on days 8-13 of the menstrual cycle. Blood samples for estradiol (E2), progesterone (P), luteinizing hormone (LH) (in a subset of 12 women), and levonogestrel (LNG) assay, were taken at 0 h and at 6, 12, 24, 72, and 168 h postinsertion. Ovulation, as defined by P > 2.5 ng/mL, occurred in 40% of subjects. A short lasting, frequently blunted, LH peak occurred within 12 h postinsertion, in all these subjects. The remaining subjects had anovulatory cycles with two distinct E2 profiles: continuously increasing E2 levels to a high mean of 414.3 pg/mL (28%), or no sustained increase in E2 (32%). Most cycles (86%) in which Norplant was inserted with high E2 levels (> 175 pg/mL) were ovulatory, whereas none were ovulatory with low E2 (< 100 pg/mL) at insertion. Based on the endocrine effects of Norplant implant insertion in the midadvanced follicular phase, in which ovulation will either occur within 48 h of insertion or will be impaired, additional contraceptive protection is necessary only for 3 days.