Pharmacokinetics of ethinylestradiol and levonorgestrel after administration of two oral contraceptive preparations

Serum concentration profiles and pharmacokinetic parameters (cmax, tmax, AUC24, AUC0-00, MRT) of ethinylestradiol (EE2) and levonorgestrel (LNG) were obtained following administration of two combined oral contraceptives. The constituents of the preparations were as follows: Gravistat (0.05 mg EE2, 0.125 mg LNG); Minisiston (0.03 mg EE2, 0.125 mg LNG). In 20 of the volunteers blood samples were taken before and up to 36 hours following the intake of a single table. In 11 women the investigation was carried out at day 21 of a treatment cycle (steady-state condition). In spite of pronounced interindividual variations of the pharmacokinetic data, a clear dependency of EE2 concentration curves on the estrogen dose of the respective preparation could be demonstrated. Under the condition of steady-state (21st day of administration) there was a slight but significant rise of the EE2 peak serum concentrations and a pronounced increase of the LNG levels, closely reflected by elevation of the AUC values. SHBG serum concentration was significantly increased by the 10th day of treatment in all subjects receiving Gravistat, whereas the mean value in the Minisiston-group did not remarkably change. Although LNG is known to be bound to SHBG with high affinity, the missing parallelism between LNG- and SHBG-concentrations suggests other (additional?) mechanisms for the elevated LNG-binding capacity in women taking combined EE2-LNG preparations.

Lunelle monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): assessment of return of ovulation after three monthly injections in surgically sterile women

The pharmacodynamic effects of medroxyprogesterone acetate (MPA) and estradiol cypionate (E2C) (MPA/E2C) (Lunelle Monthly Contraceptive Injection) on ovarian function were assessed through changes in serum progesterone concentrations. The data described here were obtained simultaneously with pharmacokinetic data presented in another article in this issue. Sixteen surgically sterile women with regular menstrual cycles were studied for one control cycle, three consecutive treatment months, and 3-5 months of follow-up. Suppression, followed by resumption of ovulation (the dynamic end point), was assessed by serum progesterone levels. Return of ovulation was presumptive based on progesterone concentrations > or = 4.7 ng/mL, as ultrasound was not used to determine the follicular/ovulatory status of these subjects. Luteal-like serum progesterone peaks were observed in all 16 women before drug administration, confirming the presence of ovulatory cycles. After the third monthly injection of MPA/E2C, progesterone concentrations were measured until demonstration of ovulation. Two women discontinued and three were lost to follow-up before this objective was achieved. Serum progesterone levels and, consequently, ovulation were suppressed beyond the entire dosing interval, indicated by the absence of any luteal-like progesterone peaks (serum progesterone concentrations did not exceed 1 ng/mL). The first normal ovulatory cycle, based on progesterone concentrations > or = 4.7 ng/mL, was observed in 11 women between days 63 and 112 after the third injection. Select medroxyprogesterone acetate parameters (i.e., area under the curve and minimum concentration) were correlated with return of ovulation. The correlation coefficients (r) were 0.757 and 0.492 for area under the curve and minimum concentration, respectively, indicating that return of ovulation is dependent, in part, on area under the curve and on the magnitude of the serum MPA trough level. In general, the higher the minimum concentration levels, the longer the time to return of ovulation. In conclusion, the return of ovulation, as confirmed by serum progesterone concentrations > or = 4.7 ng/mL, was observed as early as 63 days after the third and final monthly intramuscular injection of MPA/E2C, suggesting that consistent suppression of the hypothalamic-pituitary-ovarian axis is reversible after discontinuation of dosing.

Lunelle monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): effects of body weight and injection sites on pharmacokinetics

A new contraceptive option, medroxyprogesterone acetate (MPA) and estradiol cypionate (E2C) (MPA/E2C, Lunelle Monthly Contraceptive Injection), will soon be available for women in the US. This article reports the results of a US trial that assessed the effects of body weight and injection site on the pharmacokinetics of MPA, the progestin mediating contraceptive efficacy. This assessment was part of a nonrandomized, open-label, multicenter US study in healthy women receiving a monthly injection of MPA/E2C for 60 weeks. A total of 77 women (aged 18-47 years) at four centers participated in the pharmacokinetics assessment during the sixth or the seventh injection. For determination of serum MPA concentration-time profiles, blood samples were collected before the sixth and seventh injections (day 0) and on days 3, 7, 14, 21, and 28 after the sixth and seventh monthly administrations. For effects of injection site, MPA pharmacokinetics were compared at injection sites of the arm, hip, and leg. The pharmacokinetics of MPA, determined at the sixth and seventh injection, were not significantly affected by injection sites. The mean area under the curve (AUC0-28), however, was different between the arm and the leg injection sites; the difference was < 20%. More important, the average MPA trough concentrations (Cmin) at the fifth and sixth monthly injections were similar (range 0.42-0.51 ng/mL) for the three injection sites and well above the threshold levels of 0.10-0.20 ng/mL required to suppress ovulation. For effects of body mass index (BMI) on pharmacokinetics, women were stratified into three groups: thin/normal (BMI 18-28, n = 48), obese (BMI 29-38, n = 23), and highly obese (BMI > 38, n = 6). There were no significant differences in the pharmacokinetics of MPA among the three BMI categories. The only significant difference (p = 0.0387) was the AUC0-28 between BMI 18-28 and BMI 29-38. Because of the small sample size in the highly obese group, a reanalysis was performed by pooling subjects of the obese and highly obese groups. Results of the pooled statistical analysis remained the same. In summary, these results suggest that minor differences observed in the MPA pharmacokinetics--whether due to injection site or body weight or both--have no impact on the contraceptive efficacy of MPA/E2C, as trough concentrations (Cmin) are well above the threshold levels required to suppress ovulation. No dose adjustment is necessary based on body weight or injection site.

Lunelle monthly contraceptive injection (medroxyprogesterone acetate and estradiol cypionate injectable suspension): steady-state pharmacokinetics of MPA and E2 in surgically sterile women

The steady-state pharmacokinetics and pharmacodynamics of medroxyprogesterone acetate (MPA) and estradiol (E2, released from E2C by esterase enzymes) were characterized after administration to surgically sterile women. This report describes the pharmacokinetics of this multiple-dose and open-labeled study (pharmacodynamics are reported in a subsequent article in this issue). Women with regular menstrual cycles were studied for one control cycle, 3 consecutive treatment months, and 3-5 months of follow-up. Blood samples were drawn before each monthly dose and at specified time points after the third monthly injection. A total of 16 women were enrolled, 14 of whom completed the study. These 14 women (13 white, one black) ranged in age from 28 to 43.4 years, in body weight from 47.6 to 68.9 kg, and in height from 150 to 175 cm. Mean serum MPA concentrations peaked in the first week after administration of MPA/E2C (Lunelle Monthly Contraceptive Injection). The mean MPA Cmax and AUC0-t(last) were 1.25 ng/mL and 32.13 ng.day/mL, respectively. Serum MPA concentrations declined with a mean terminal half-life of 14.7 days, indicating that absorption from the injection site is prolonged after administration of MPA/E2C. The time for MPA concentrations to fall below the lower limit of quantitation (i.e., < 10 pg/mL) after the third injection ranged from 63 to 84 days. The average MPA trough (Cmin' day 28) concentrations for the three consecutive monthly injections ranged from 0.44 to 0.47 pg/mL, indicating that steady-state conditions were achieved after the first injection. The MPA Cmin values were well above threshold levels required to suppress ovulation throughout the injection interval. Absorption of E2 from the injection site was also prolonged after injection of MPA/E2C. Mean concentrations of E2 peaked at approximately 2 days after the third injection, and the average Cmax was 247 pg/mL. Serum E2 levels declined with a terminal half-life of approximately 8 days; E2 levels returned to baseline (typically, approximately 100 pg/mL) by 14 days after each injection. The average trough (Cmin' day 28) levels for E2 ranged from 40 to 55 pg/mL. The results of this study demonstrate that steady-state conditions are achieved after the first injection of MPA/E2C; no further MPA or E2 accumulation occurs beyond the first injection. Furthermore, the E2 peak observed after injection of MPA/E2C is similar to the nontreated preovulatory E2 range and returns to baseline levels by approximately 14 days after injection.

The effects of rifampin and rifabutin on the pharmacokinetics and pharmacodynamics of a combination oral contraceptive

BACKGROUND

Rifampin (INN, rifampicin), a CYP34A inducer, results in significant interactions when coadministered with combination oral contraceptives that contain norethindrone (INN, norethisterone) and ethinyl estradiol (INN, ethinylestradiol). Little is known about the effects of rifabutin, a related rifamycin.

OBJECTIVES AND METHODS

The relative effects of rifampin and rifabutin on the pharmacokinetics and pharmacodynamics of ethinyl estradiol and norethindrone were evaluated in a prospective, randomized, double-blinded crossover study in 12 premenopausal women who were on a stable oral contraceptive regimen that contained 35 microg ethinyl estradiol/1 mg norethindrone. Subjects were randomized to receive 14 days of rifampin or rifabutin from days 7 through 21 of their menstrual cycle. After a 1-month washout period (only the oral contraceptives were taken), subjects were crossed over to the other rifamycin.

RESULTS

Rifampin significantly decreased the mean area under the plasma concentration-time curve from time 0 to 24 hours [AUC(0-24)] of ethinyl estradiol and the mean AUC(0-24) of norethindrone. Rifabutin significantly decreased the mean AUC(0-24) of ethinyl estradiol and the mean AUC(0-24) of norethindrone. The effect of rifampin was significantly greater than rifabutin on each AUC(0-24). Despite these changes, subjects did not ovulate (as determined by progesterone concentrations) during the cycle in which either rifamycin was administered. Levels of mean follicle-stimulating hormone increased 69% after rifampin.

CONCLUSION

In this study, rifampin (600 mg daily) was a more significant inducer of ethinyl estradiol and norethindrone clearance than rifabutin (300 mg daily), but neither agent reversed the suppression of ovulation caused by oral contraceptives. The carefully monitored oral contraceptive administration and the limited exposure to rifamycins may restrict the application of this study to clinical situations.

Long-term depot-medroxyprogesterone acetate and bone mineral density

The association between long-term use of depot-medroxyprogesterone acetate (DMPA) and bone mineral density (BMD) has been controversial, as seen in three case-control studies in New Zealand, Thailand, and the United Kingdom. In the present case-controlled study of BMD, a group of 67 Chinese women who had used DMPA from 5-15 years was compared with 218 women of the same age range who had not used any steroidal hormones. DMPA users were found to have a significantly lower BMD at lumbar vertebra (L2-4) (0.93 g/cm2), neck of femur (0.69 g/cm2), trochanter (0.59 g/cm2), and Ward's triangle (0.58 g/cm2), as compared with the control group, whose corresponding BMD values were 1.03 g/cm2, 0.83 g/cm2, 0.71 g/cm2, and 0.78 g/cm2, respectively (p < 0.001). The average percentage of bone loss per year was estimated to be 1.1% in L2-4, 2.3% in neck of femur, 2.4% in trochanter, and 3.5% in Ward's triangle. The percentage of bone loss in L2-4 was found to be more pronounced with age. This study provided information that the use of DMPA in a Chinese group for > 5 years in associated with bone loss, and a prospective study is needed to confirm these data, which are different from two case-control studies.

Bone density among long-term users of medroxyprogesterone acetate as a contraceptive

The bone density (BD) of 72 women using depot-medroxyprogesterone acetate (DMPA) for at least 1 year was compared with that of 64 women who were not users of hormonal contraceptives. The BD of lumbar spine, femoral neck, Ward's triangle, and trochanter was measured by dual energy X-ray absorptiometry (DEXA-LUNAR DPX). Estradiol (E2) concentrations were measured by radioimmunoassay (RIA). The mean age of DMPA users and nonusers was 31.8 and 31.1 years, respectively. Mean E, was 55.7 pg/mL for users and 149.9 pg/mL for controls (p < 0.001). The BD was significantly lower for DMPA users than for controls in all sites (p < 0.01). In addition, young adult T-scores in the lumbar spine were significantly lower among DMPA users than in controls (p < 0.01). Differences were maintained in a subsample of 47 women per group paired by age and body mass index (BMI). Multiple regression analysis showed that older age, lower BMI, and longer amenorrhea were associated with lower BD in the femoral neck, whereas lower BMI and use of DMPA were associated with lower BD in the lumbar spine.

Effect of desogestrel-containing oral contraceptives on vascular reactivity and catecholamine levels

The modifications induced by new oral contraceptives (OC) on blood pressure, great vessel vascular reactivity by color Doppler, and catecholamine levels were investigated. Young healthy women not taking OC (n = 22; controls) or receiving, for > or = 6 months, OC containing desogestrel with either 30 micrograms (n = 14) or 20 micrograms of EE (n = 8) were enrolled. Blood pressure measured at rest in supine position was similar between controls and OC users. The pulsatility index (PI), an indirect index of resistance to blood flow, of axillary artery was significantly higher (p < 0.05) in 30 micrograms than in 20 micrograms EE OC users or controls. A similar trend, albeit not significant, was observed for the internal carotid artery PI. Norepinephrine (p < 0.01) and dopamine (p < 0.05) but not epinephrine levels, were lower in 30 micrograms EE OC users than in 20 micrograms EE OC users or controls. Thus, both 20 micrograms and 30 micrograms EE OC had no negative effect on blood pressure, but the 30 micrograms EE OC tended to increase great vessel resistance to blood flow, independently of catecholamine levels.

A 2-year comparative study of endometrial histology and cervical cytology of contraceptive implant users in Birmingham, UK

The objectives of this study were to evaluate the endometrial histology and cervical cytology of users of two contraceptive implants releasing etonogestrel/3-keto-desogestrel (Implanon) and levonorgestrel (Norplant) in West Midlands (UK) users. A 2-year prospective randomized design was used to study 60 implant users. Endometrial histology and cervical cytology were compared before insertion and after 12 and 24 months. At the end of 12 months, the majority of samples were inactive/weakly proliferative in both groups. At the end of 24 months, this remained unchanged in the Implanon group whereas the pattern was more diverse in the Norplant group. Endometrial thickness was significantly reduced in both groups during treatment. Cervical cytology remained unchanged. It is concluded that, after 2 years, there was no evidence of an increasing risk of endometrial hyperplasia, endometrial carcinoma, cervical intra-epithelial neoplasia or cervical carcinoma in either of the two groups of implant users.

Precise measurements of intrauterine vascular structures at hysteroscopy in menorrhagia and during Norplant use

Using currently available equipment for panoramic hysteroscopy, the size of images viewed cannot be accurately judged because of the magnifying and distorting effects of the objective lens. This study has demonstrated that magnification by the hysteroscope lens can alter the apparent size of images by up to 27%. An additional effect of lens distortion can alter the apparent size of images viewed by up to 28%, depending on the position of the image in the field of view. These effects are independent and may be additive. Thus, the apparent size of intrauterine structures at hysteroscopy may bear little resemblance to their actual size. Image-correction methods are described which reduce the effects of image magnification on the apparent size of an object viewed through the hysteroscope to 7%, and the effect of distortion to 3 %. This technique can greatly improve the accuracy of measurement at hysteroscopy, and has been utilized in this study for the precise measurement of superficial endometrial vascular diameter (mean+/-SEM) in 34 Norplant users (120+/-11.6 microm) and 20 women with spontaneous menorrhagia (74+/-7.2 microm). It has also confirmed the presence of scattered dilated vessels (up to 777 microm in diameter) on the endometrial surface in some Norplant users.

Contraception with two levonorgestrel rod implants. A 5-year study in the United States and Dominican Republic

A 5-year trial of a two-rod contraceptive implant, which releases the progestin levonorgestrel (LNG rod), was conducted at four clinics with 594 women. Mean age and weight at admission were 25.5 years and 62.4 kg, respectively. Consent to continue through 5 years was sought and obtained when the 3-year cumulative pregnancy rate proved to be 0.8 per 100. No pregnancies occurred in the fourth or fifth years. The 5-year cumulative pregnancy rate was, therefore, 0.8 per 100 with an annual average pregnancy rate below 2 per 1000 women. Prolonged bleeding/spotting (8.2% of subjects) and irregular bleeding (5.6%) were the most frequently cited medical reasons for removal. Removals for headache (4.7%) and weight change (4.0%) were the next most frequent medical reasons. Between 1% and 2% of subjects during the 5-year trial sought removals for each of the following conditions: mood changes, lower abdominal pain, depression, or pain at the implant site. The mean annual continuation rate during the study was 77 per 100. Use per woman averaged 2.96 years. Mean removal time was 5.9 +/- 0.6 min. These data indicate that, for a 5-year period, the two LNG rod implants are equivalent to the six Norplant capsule implants with respect to safety and efficacy parameters, but permit easier and more rapid implant removal.

Pharmacokinetics of etonogestrel released from the contraceptive implant Implanon

Eight healthy women between 22 and 40 years of age participated in this prospective open study of 2 years' duration. Either on or between days 1 to 7 of a spontaneous menses, an intravenous bolus dose of 150 micrograms etonogestrel (3-ketodesogestrel) was given. During days 1-5 of a subsequent spontaneous cycle, the single-rod contraceptive implant (Implanon) was inserted in the upper arm of the volunteer. One year after placement of the implant, another intravenous bolus dose was given (implant in place), and a third bolus dose was given after 2 years, with the implant removed. Frequent serum sampling immediately after the intravenous dosings of etonogestrel was done to study the primary pharmacokinetic parameters, i.e., volume of distribution and clearance, allowing the calculation of the absorption rate and bioavailability of the implant, as a function of time. Results showed that etonogestrel released from Implanon has an absorption rate of approximately 60 micrograms/day after 3 months, which slowly decreases to 30 micrograms/day at the end of 2 years. The bioavailability over this period of time was constant and close to 100%. The clearance remained around 7.5 L/h. With a bioavailability and clearance that remained constant, it may be concluded that there is no accumulation of etonogestrel.

Experience of Thai women in Bangkok with Norplant-2 implants

A prospective study of the Norplant-2 contraceptive subdermal implant system was conducted in Bangkok, Thailand. The objective of the study was to evaluate the efficacy, adverse effects, and overall acceptability of Norplant-2 implants. A total of 140 women were enrolled in a 3-year clinical trial. The mean age was 29 years. Of all the acceptors, 70% had completed primary school. The continuation rates at years 1, 2, and 3 were, respectively, 94%, 89%, and 83%. No accidental pregnancies occurred throughout the 3 years of use in this study. Personal reasons were the leading cause for termination of Norplant-2 implant use. The 3-year cumulative termination rate for personal reasons was 7.2%. These personal reasons were divorce, husband having vasectomy, and moving away from the study area. The other leading cause for termination was medical reasons; acne, headache, and pain at the implant site were the complaints. The termination rate for medical reasons in year 3 of the study was 4.6%. Prolonged menstrual flow was the other main reason for termination. The 3-year cumulative termination rate for menstrual irregularities was 3.8%. In this study, the cumulative termination for planned pregnancy at the end of the year 3 was only 1.6%. The incidence of difficult removals was 8%. Breakage of the rods on removal was encountered in the majority of these cases. The study findings presented suggest that the Norplant-2 implants are highly effective with high continuation rates. The Norplant-2 system could become another choice of long acting reversible contraception for Thai women.

Sex hormone binding globulin and free levonorgestrel index in the first week after insertion of Norplant implants

Levonorgestrel has an inhibitory effect on sex hormone binding globulin (SHBG). This decrease in SHBG leads to an increase in the free levonorgestrel index (FLI), which has a stronger biological effect. The interaction between serum levels of levonorgestrel and SHBG in long-term users of Norplant implants has been described. This study was designed to understand the same interaction immediately after the insertion of the implants, in a group of 16 women, sampled at 0 and 6 h and at 1, 3, and 7 days after Norplant implant insertion. Peak serum levonorgestrel levels were achieved at 24 h after insertion, remaining stable on day 3 and decreasing by > 10% by day 7. SHBG did not change during the first 24 h, but decreased by 19% and 60% on days 3 and 7, respectively. FLI more than doubled from day 1 to day 7 after insertion. The large decrease in SHBG and doubling of FLI is not followed by a similar reduction in levonorgestrel, which is hard to explain without an increase in the release rate of the steroid from the capsule.

Effect of oral contraceptive progestins on serum copper concentration

OBJECTIVES

Recent epidemiologic studies have shown an increased mortality from cardiovascular diseases in people with higher serum copper levels. Even though higher serum copper concentration in women using oral contraceptives is well known, there is still uncertainty about the influence of newer progestin compounds in oral contraceptives on serum copper concentration. This issue is of particular interest in the light of recent findings of an increased risk of venous thromboembolism in users of oral contraceptives containing newer progestins like desogestrel compared to users of other oral contraceptives.

DESIGN

Cross-sectional epidemiologic study. Examinations included a detailed questionnaire on medical history and lifestyle factors, a seven day food record, and blood samples.

SETTING

National health and nutrition survey among healthy people living in private homes in West Germany in 1987-1988.

SUBJECTS

Nonpregnant and nonlactating women aged 18-44 y (n = 610).

RESULTS

Overall, the use of oral contraceptives was positively associated with serum copper concentration in by bi- and multivariable linear regression models with log-transformed values of serum copper concentration as dependend variable and oral contraceptive preparations and potential confounding variables as independent variables. Serum copper concentration in women using oral contraceptives varied more strongly by different progestin compounds than by estrogen contents. The highest increase of serum copper was seen in women using oral contraceptives containing antiandrogen progestins (55%; 95% CI: 37-76%), followed by desogestrel (46%; 95% CI: 36-56%), norethisteron/lynestrenol (42%; 95% CI: 29-57%), and levonorgestrel (34%; 95% CI: 24-45%).

CONCLUSION

While elevated serum copper concentration was found in users of all types of oral contraceptives, elevation was more pronounced among women taking oral contraceptives with antiandrogen effective progestins like antiandrogens or third generation oral contraceptives containing desogestrel. Further investigation is required to shed light on the possible role of high serum copper concentration in increasing cardiovascular or thrombotic risk of women using oral contraceptives.

Myocardial infarction and stroke in young women: what is the impact of oral contraceptives?

Recent discussions have centered on the small apparent risk increase for venous thromboembolism found with newer oral contraceptives (third-generation oral contraceptives containing the progestins desogestrel and gestodene) compared with older oral contraceptives (second-generation). This article reviews the studies addressing the association between oral contraceptive use and thromboembolic conditions affecting the arterial system, ischemic stroke, and myocardial infarction. Differences are found between a US database study, which showed no risk of ischemic stroke or myocardial infarction associated with low-dose oral contraceptive use, and the European studies, which showed oral contraceptive use in general to be associated with increased risks of ischemic stroke and myocardial infarction. The European studies showed no difference between oral contraceptive generations with respect to the occurrence of ischemic stroke; however, the risk of myocardial infarction associated with oral contraceptive use was consistently lower for third- than for second-generation oral contraceptives. Although there seems to be no differential risk of ischemic stroke associated with oral contraceptive generations, third-generation oral contraceptives appear to be consistently associated with no excess risk of myocardial infarction. In all instances, however, cardiovascular risk factors other than oral contraceptive use play the predominant role in the occurrence of ischemic stroke and myocardial infarction.

Bias versus causality: interpreting recent evidence of oral contraceptive studies

Late in 1995 and early 1996, 4 epidemiologic studies were published that resulted in a crude mean weighted relative risk of approximately 2 when third-generation oral contraceptives were compared with second-generation oral contraceptives as risk factors for venous thromboembolism. This article reviews empirical evidence on bias or systematic error that may have influenced the estimates of association. The Bradford-Hill criteria to distinguish causality from an observed association were used to consider whether third-generation oral contraceptives cause an apparent excess in the occurrence of venous thromboembolism. Bias is more likely than a causal relationship to explain the associations observed for venous thromboembolism. For myocardial infarction, bias may mask the full benefit of third-generation oral contraceptives. For stroke, the question of causality is moot because statistically significant differences between third- and second-generation products have not been detected. The clinical importance and the public health significance of any differences among the various products with respect to adverse cardiovascular outcomes are trivial and undetectable because of the extremely low incidence of those disorders among users of oral contraceptives. The oral contraceptive pill is 99.9% effective when used correctly. All oral contraceptives on the market are safe and getting safer.

Oral contraceptives and venous thromboembolic disease: the findings from database studies in the United Kingdom and Germany

OBJECTIVE

Three research articles published in late 1995 and early 1996 suggested that oral contraceptives containing either of the newer progestogens (gestodene or desogestrel) could be associated with an increased risk of venous thromboembolism. During the months after the initial publications, the results have been scrutinized with great care and further studies have been published. The findings of 2 recent database studies, 1 in the United Kingdom and 1 in Germany, are presented in this article.

PATTERNS OF USE

The average age of users of combined oral contraceptives in Germany was 27 years, compared with 26 years in the United Kingdom. In Germany the use of gestodene-based products was lower than that in the United Kingdom. In the United Kingdom the users of desogestrel with 20 microg ethinyl estradiol (Mercilon) were older than the users of desogestrel with 30 microg ethinyl estradiol (Marvelon).

CRUDE INCIDENCE

The crude incidence of venous thromboembolism in the UK study was 4.1 cases/10,000 woman-y exposure to combined oral contraceptives. In Germany it was 4.2 cases/10,000 woman-y. In Germany the rates among users of second-generation combined oral contraceptives were higher than those among users of third-generation products. The reverse was the case in the United Kingdom. In the United Kingdom the crude incidence rates were higher for the 20 microg estrogen desogestrel product than for the 30 microg product. CASE-CONTROL ANALYSIS: The adjusted odds ratios in the UK study did not show significant increases for desogestrel or gestodene compared with levonorgestrel products. There were inconsistencies in the results among centers in the 2 international studies (the World Health Organization and Transnational studies). In both there was a consistent inverse dose-response relationship with estrogen in all centers.

CONCLUSION

The limitations of the observational studies are such that the hypothesis that the newer progestogens are more likely to cause venous thromboembolism cannot be proved.

Effects on hemostatic variables of desogestrel- and gestodene-containing oral contraceptives in comparison with levonorgestrel-containing oral contraceptives: a review

In some studies third-generation oral contraceptives have been reported to be associated with a higher risk of venous thromboembolism than are second-generation oral contraceptives, whereas recent, more refined studies have not confirmed this. The reasons for the alleged differences are under discussion, and differential effects on hemostasis have been proposed. Eighteen studies comparing second- and third-generation oral contraceptives with respect to their effects on hemostasis were analyzed. Significant changes from baseline were reported for many variables with both second- and third-generation oral contraceptives without significant between-group differences. Also, in a combined analysis of nonsignificant changes, no consistent pattern of change emerged for any marker, with the exception of higher factor VII levels associated with third-generation oral contraceptives. However, factor VII is not related to venous thromboembolism risk. In addition, 1 cross-sectional study with an unvalidated assay reported a higher ratio of activated protein C sensitivity with third-generation oral contraceptives. Only 2 components of the hemostatic system (factor VII and activated protein C sensitivity ratio) emerged as potentially differentially affected by second- and third-generation oral contraceptives; the association with venous thromboembolism risk is questionable in the former case and unknown in the latter.

Thrombotic diseases in young women and the influence of oral contraceptives

OBJECTIVE

In the evaluation of the clinical impact of thrombotic diseases in young women, age-specific incidence rates must be calculated for both arterial and venous thrombotic diseases, but also the case-fatality rate and figures for the clinical consequences among those who survive thrombosis must be included. The aim of this analysis was to quantify the clinical impacts of both arterial and venous thrombotic diseases among young, nonpregnant women and thereafter to assess the influences of oral contraceptives on these measures.

STUDY DESIGN

Nationwide register data on the morbidity and mortality of venous thromboembolism, myocardial infarction, and thrombotic stroke in Denmark, 1980-1993, and 3 ongoing case-control studies to assess the influence of oral contraceptives on the risk for development of these thrombotic diseases.

RESULTS

In women 15-29 years old venous thromboembolism is about twice as common as arterial complications, whereas in women 30-44 years old the number of arterial complications exceeds that of venous diseases by about 50%. The mortality rate from arterial diseases is 3.5 times higher than that from venous diseases among women <30 years old and 8.5 times higher than that from venous diseases in women 30-44 years old. The proportion of women with a significant disability among women who had an arterial complication was about 30%; the proportion was about 5% among women with venous thromboembolism.

CONCLUSION

Anticipating a differential influence on venous and arterial diseases from oral contraceptives with second- and third-generation progestogens, it was calculated that users of oral contraceptives with second-generation progestogens had 30% greater increased risk of thrombotic diseases, 260% greater increased risk of thrombotic deaths, and 220% greater increased risk of thrombotic disability than users of oral contraceptives with third-generation progestogens.

Effect of two oral contraceptives containing ethinyl estradiol and gestodene or norgestimate on different lipid and lipoprotein parameters

The effect of a triphasic oral contraceptive containing ethinyl estradiol and gestodene (EE/GSD) on various lipid and lipoprotein parameters was compared with that of a monophasic formulation containing 35 micrograms ethinyl estradiol and 250 micrograms norgestimate (EE/NGM). Blood samples were collected from 46 women on days 2, 11, and 21 of the preceding control cycle and of the third, sixth, and twelfth treatment cycles. There was no significant difference between formulations with regard to the influence on any measured parameter. As compared with controls, a significant increase was observed in the plasma levels of total triglycerides (24-78%), total phospholipids (7-20%), very low density lipoprotein (VLDL) triglycerides (61-76%), VLDL-phospholipids (14-60%), low density lipoprotein (LDL) triglycerides (8-35%), LDL-phospholipids (28-30%), high density lipoprotein (HDL) cholesterol (8-16%), HDL 3-cholesterol (11-20%), HDL-triglycerides (17-66%), HDL-phospholipids, HDL 3-phospholipids (7-11%), apolipoprotein (apo) A-I (5-20%) and apo A-II (10-40%) during treatment with both formulations. In contrast, the LDL-cholesterol levels were significantly decreased. These changes in lipid metabolism appear to reflect a predominance of the effect of the estrogen component. The results indicate that both low dose oral contraceptives containing different progestins and different amounts of EE do not exert a deleterious effect on lipoprotein metabolism, as high HDL-cholesterol and low LDL-cholesterol levels are known as low risk factors of cardiovascular disease. In contrast to endogenous hypertriglyceridemia, an EE-induced rise in triglyceride levels does not appear to increase cardiovascular risk if LDL is not increased.

Resistance to activated protein C, highly prevalent amongst users of oral contraceptives with venous thromboembolism

OBJECTIVE

Inherited resistance to activated protein C (APC resistance), which is caused by a single point mutation in the factor V gene, is a frequent risk factor for venous thromboembolism. The aim of this study was to determine the prevalence of APC resistance and other coagulation disorders in fertile women with venous thromboembolism and also the risk factors these women had been exposed to in connection with thromboembolic events.

DESIGN

A retrospective, case-control study of 36 month duration.

SETTING

The study was carried out at Blekinge Hospital, Karlskrona, Sweden.

SUBJECTS

The study population comprised 27 fertile women age 16-47 years with thromboembolic complications, referred to the department of Internal Medicine at Blekinge Hospital in Karlskrona during a 36-month period.

RESULTS

APC resistance was found in 10 out of 27 women. APC resistance was associated with treatment with oral contraceptives in five out of six women and with pregnancy in one of seven women. All women with resistance to APC developed venous thrombosis in association with a predisposing situation (risk situation) such as surgery, trauma, immobilization, pregnancy, inflammatory state or the use of oral contraceptives. Amongst women not resistant to APC, all but one developed thrombosis in connection with a risk situation.

CONCLUSION

APC resistance was found to be highly prevalent amongst fertile women with a history of thromboembolic complication occurring during their use of oral contraceptives.

Bone density in long term users of depot medroxyprogesterone acetate

OBJECTIVE

To identify any adverse effect on bone density in long term users of depot medroxyprogesterone acetate (DMPA) for contraception.

DESIGN

Cross-sectional measurement of bone density in users with amenorrhoea of more than one year or any woman using DMPA for more than five years.

SETTING

Community Family Planning Clinics in Portsmouth and Manchester.

POPULATION

One hundred and eighty-five women aged 17-52 years (mean 33.3 years) who had used DMPA for between 1 and 16 years and were attending the clinics for further injections, between August 1994 and August 1996.

METHODS

Dual energy X-ray measurement of bone density of femoral neck and lumbar spine, and venous blood sample taken just prior to the next injection of DMPA.

MAIN OUTCOME MEASURES

Bone density of femoral neck and lumbar spine and serum oestradiol in relationship to years of DMPA use and duration of amenorrhoea.

RESULTS

Most women (n=153) had serum oestradiol levels < 150 pmol/l. Despite this, the mean bone density of the lumbar spine compared with the population mean for women aged 20-59 years gave a Z score (95% CI) of -0.332 (-0.510 to -0.154). There was no significant difference in the mean density of the femoral neck from the normal population mean.

CONCLUSION

Despite amenorrhoea and low serum oestradiol, this sample of long term DMPA users had bone density only minimally below the normal population mean. We therefore found no clinically important adverse effect on bone density and therefore no reason to recommend bone conserving measures, such as add-back oestrogen.

Introduction of cyclofem once-a-month injectable contraceptive in Mexico

A large introductory study of Cyclofem, a once-a-month injectable contraceptive, was conducted in three Mexican provinces. A total of 3457 healthy women participated: 640 women from rural areas (community-based component) and 2817 women from urban and suburban areas (health center-based component). A total of 20,316 women-months of treatment experience were accumulated during a one year period. Cyclofem proved its use-effectiveness (pregnancy rate of 0.03%) and its safety under routine service conditions of family planning facilities in Mexico. The overall life table continuation rate at 1 year was 26.1%. Higher continuation rates were observed in the community-based component (36.6%) as compared to the health center component (23.7%). The most common reason for method discontinuation was change of address. Only 15% of the discontinuations were attributable to the injectable contraceptive method, with the overall 1 year discontinuation rate for bleeding problems (including amenorrhea) was < 11%. These observations underscore the importance of appropriate counseling and follow-up measures, providing convenient access to repeat injections, and other service delivery issues related to continuation of Cyclofem. The results of this trial have once again demonstrated that Cyclofem is a highly effective method with an acceptable side effect profile. In addition, the study provided the elements for its approval by local health authorities and its inclusion into the Ministry of Health Family Planning Program.

Influence of hormonal contraceptives on microbial flora of gingival sulcus

To determine a possible influence of two different hormonal contraceptives on bacterial microflora of gingival sulcus, subgingival plaque samples of 29 healthy women aged between 20 and 32 years were investigated bacteriologically before subjects took a contraceptive and 10 and 20 days after subjects started the medication. In 14 women, and oral contraceptive containing 0.02 mg ethinyl estradiol and 0.15 mg desogestrel (preparation A) was used, and 15 women took a contraceptive containing 0.03 mg ethinyl estradiol and 2.00 mg dienogest (preparation B) daily over 21 days. There were no changes in clinical parameters of the teeth investigated during 3 weeks of the study. The periodontopathogenic bacteria Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were never detected throughout the study. On the other hand, the periodontopathogenic species Prevotella intermedia was found in plaque samples of 22 women. The content of this microorganism showed only a little change between the pretreatment period and plaque sampling after 10 days of contraceptive treatment, but a striking increase occurred after 20 days of contraceptive treatment, especially in the preparation A group. In this respect, there was a significant difference between preparations A and B.

Pharmacokinetics of medroxyprogesterone acetate after single and multiple injection of Cyclofem in Chinese women

To provide pharmacokinetic data for safety evaluation on prolonged treatment with Cyclofem, which contains 25 mg medroxyprogesterone acetate (MPA) and 5 mg estradiol cypionate in 0.5 mL microcrystalline aqueous suspension, the pharmacokinetic profiles of MPA after single and multiple administration of this monthly injectable contraceptive were investigated in Chinese women. Nine healthy fertile women received Cyclofem based on a once-a-month regiment for up to 1 year. Blood samples were collected immediately prior to drug administration and on days 1, 3, 5, 7, 14, 21, and 28 after injection. After the 1st, 6th, and 12th injection, the maximum serum concentrations (Cmax) of MPA were observed on days 3.4 +/- 0.9, 4.3 +/- 2.2, and 3.7 +/- 2.6, respectively. Cmax of serum MPA during the 1st, 6th, and 12th treatment cycles were 3.75 +/- 1.27, 5.54 +/- 1.79, and 5.55 +/- 1.80 nmol/L, whereas the areas under the curve (AUC0-28 days) were 55.84 +/- 28.15, 95.45 +/- 26.56, and 98.81 +/- 21.84 nmol/L.day, respectively. There was significant interindividual variation in the pharmacokinetics of MPA after intramuscular injection of Cyclofem. No significant change was demonstrated in mean residence time (MRT) of MPA after single and multiple injection. There was a tendency of increase in Cmax and AUC0-28 days of MPA during the first 6 months of treatment, whereas no further enhancement was found between the 6th and 12th injection (p > 0.05). Peak levels of estradiol (E2) observed in Cyclofem users were within the normal range of the preovulatory phase. Results of this long-term study suggest that no drug accumulation occurred after repeated administration of Cyclofem in the Chinese women.

Progestin receptor isoforms and prostaglandin dehydrogenase in the endometrium of women using a levonorgestrel-releasing intrauterine system

This study has examined endometrial tissue in 14 normal women prior to insertion of a levonorgestrel-releasing intrauterine system (LNG-IUS) and thereafter longitudinally for up to 12 months post-insertion. The specific endpoints examined by immunohistochemistry were progesterone receptor (PR) subtypes A + B, oestrogen receptor (ER) and prostaglandin dehydrogenase (PGDH). Two antiprogesterone receptor antibodies, one specific to PR(B) subtype and the other to PR subtype A + B, were employed to examine the localization of both PR isoforms. The activity of PGDH, a progesterone dependent enzyme, was also measured. ER and PR(A+B) and PR subtype B were significantly down-regulated in glands and stroma in the presence of continuous intrauterine LNG delivery. There was an apparent increase in PR(A) immunoreactivity in endometrial glands between 6 and 12 months post-insertion. Consistent with down-regulation of both isoforms of PR was reduced glandular PGDH immunostaining following LNG-IUS insertion, and PGDH activity (as measured by metabolism of excess substrate in vitro). Furthermore, PGDH activity, known to be localized in the glands, significantly increased (P < 0.05) at 12 months post-insertion, coinciding with the observed increase in glandular PR(A+B) immunoreactivity at this time. Since the LNG-IUS suppresses the PR(B) so strongly, PR(A) is likely to be the subtype that mediates long term LNG action in the endometrium. PR(B) is the more suppressed of the two subtypes, and only PR(A) rises along with PGDH activity. Alterations to normal endometrial morphology and function, e.g. perturbation of normal sex steroid receptor expression, following exposure to high concentrations of local LNG, may play a role in the aetiology of bleeding disorders associated with the LNG-IUS. Further elucidation of local uterine mediators involved in the mechanism of bleeding problems is required.

Morphological and functional features of endometrial decidualization following long-term intrauterine levonorgestrel delivery

Irregular bleeding remains a common reason for the discontinuation of progestin-only contraception. The levonorgestrel releasing intrauterine system (LNG-IUS) has profound morphological effects upon the endometrium. Specific features are gland atrophy and extensive decidual transformation of the stroma. Morphological changes in the endometrium may be associated with perturbation of mechanisms regulating normal endometrial function. This study describes endometrial stromal and glandular features prior to and up to 12 months following insertion of the LNG-IUS. Comparison is made with first trimester decidua. In order to elucidate further mechanisms governing endometrial function with local intrauterine delivery of LNG, we here report histological features consistent with decidualization; a significant increase in granulocyte-macrophage colony stimulating factor (GM-CSF) immunoreactivity in decidualized stromal cells; glandular and stromal prolactin receptor expression and an infiltrate of CD56 + large granular lymphocytes and CD68 + macrophages. We are unaware of previous reports which have documented longitudinally both morphological and functional observations in endometrium exposed to local intrauterine levonorgestrel delivery. These studies demonstrate that long-term administration of intrauterine levonorgestrel results in features of altered morphology and function. No correlation was apparent between the end points in the study and the bleeding patterns described by the subjects. Further evaluation of these features in the context of menstrual bleeding experience may contribute to a better understanding of this troublesome side-effect which often leads to dissatisfaction and discontinuation of the intrauterine system.

Gabapentin does not interact with a contraceptive regimen of norethindrone acetate and ethinyl estradiol

Anticonvulsants that induce hepatic metabolism increase clearance of oral contraceptive hormones and thereby cause contraceptive failure. Gabapentin is not metabolized in humans and has little liability for causing metabolic-based drug-drug interactions. In healthy women receiving 2.5 mg norethindrone acetate and 50 microg ethinyl estradiol daily for three consecutive menstrual cycles, concurrent gabapentin administration did not alter the steady-state pharmacokinetics of either hormone. Thus, gabapentin is unlikely to cause contraceptive failure.

Newer oral contraceptives and the risk of venous thromboembolism

Research on the relationship between venous thromboembolism and the progestagen content of combined oral contraceptives has pointed to an increase in risk associated with products containing desogestrel and gestodene. Although many biases must have been at play in these nonexperimental studies, the errors that have been suggested and examined are not of a sufficient magnitude to account for the observed results. The most plausible explanation of the available data is that combined oral contraceptives containing desogestrel and gestodene carry a very small risk of venous thromboembolism, which exceeds the even smaller risk carried by products containing levonorgestrel. The position of norgestimate is uncertain.

Timing of onset of contraceptive effectiveness in Depo-Provera users: Part I. Changes in cervical mucus

OBJECTIVE

To evaluate the changes in cervical mucus within the first hours or days after depot medroxyprogesterone acetate (MPA) injection so as to estimate the time at which cervical mucus becomes hostile enough to prevent pregnancy.

DESIGN

Multicenter, clinical descriptive study.

SETTING

Family planning clinic.

PATIENT(S)

Thirty women who were between days 8 and 13 of their menstrual cycle and who had requested Depo-Provera were enrolled in the study.

INTERVENTION(S)

Cervical mucus and blood samples were obtained; transvaginal ultrasonography was performed.

MAIN OUTCOME MEASURE(S)

Cervical mucus scores, sperm penetration distances, ovarian follicular size, and serum levels of progesterone and estradiol.

RESULT(S)

From 6 to 24 hours after injection, there was a sharp decline in the cervical mucus score for most of the subjects. All subjects exhibited poor mucus on day 3 after injection, and by day 7, all subjects had zero scores, with the exception of two outliers on each day. Sperm penetration, as measured by the vanguard sperm distance, was already poor (< 1 cm) in 7 of the 30 subjects at the time of injection and was reduced progressively up to 24 hours after injection, when only four subjects had a sperm penetration of > 1 cm. A rapid decline in the estimated number of sperm was observed at 12 hours and more so at 24 hours in the majority of subjects.

CONCLUSION(S)

The data presented in this report confirmed that depot MPA causes profound changes in cervical mucus after injection. Although very little change was seen at 6 hours, alterations were observed subsequently, with 90% of the subjects showing a poor cervical mucus score 24 hours after administration of the progestin. No reliable clinical marker is available to identify in which women depot MPA might exert its effect on cervical mucus within 3 days. Thus, we believe that at present, women should be informed of this uncertainty and should use a backup method of contraception for 7 days when the first injection of depot MPA is provided after the seventh day of the menstrual cycle.

Timing of onset of contraceptive effectiveness in Norplant implant users. Part I. Changes in cervical mucus

OBJECTIVE

To provide scientific data regarding the changes in cervical mucus within the first hours to days after Norplant implant insertion and to estimate when the cervical mucus is hostile enough to suggest a contraceptive effect.

DESIGN

Multicenter, clinical descriptive study.

SETTING

Family planning clinics.

PATIENT(S)

Forty-two women who were between days 8 and 13 of their menstrual cycle and who had requested Norplant implants were admitted to the study.

INTERVENTION(S)

Cervical mucus and blood samples were obtained.

MAIN OUTCOME MEASURE(S)

Cervical mucus scores, sperm penetration distances, and serum levels of progesterone, estradiol, and levonorgestrel.

RESULT(S)

The median cervical mucus score observed at baseline was 6 ("fair"), indicating that the mucus was already somewhat hostile before insertion of the Norplant implants. The median scores declined to 5 at 12 and 24 hours and continued to decrease through day 7 to 2 ("poor"), a score that is judged as hostile to sperm penetration. Overall, 73% of all subjects had a poor cervical mucus score by 3 days after insertion; at 7 days after insertion, 90% exhibited poor mucus and none had a good score. There was a substantial drop in the overall median distance traveled by the vanguard sperm after 12 hours for each cervical mucus score grouping. The distance traveled decreased rapidly between 12 and 24 hours to < 0.5 cm in subjects with fair and poor mucus, and by day 3, 91% of the subjects exhibited poor sperm penetration.

CONCLUSION(S)

On the basis of our findings, deterioration of the quality of the cervical mucus and sperm penetration is evident by 24 hours after insertion, although not to a level that would suggest adequate protection until 72 hours after insertion. Therefore, we are confident in recommending that backup methods of contraception (e.g, condoms) need not be used for more than 3 days after insertion, even when the implants are inserted close to ovulation. These findings provide policy makers, clinic managers, and clinicians with important information about how they can improve client access to Norplant implants.

The risks of venous thromboembolic disease among German women using oral contraceptives: a database study

This study investigated the risk of venous thromboembolic disease (VTE) between second and third generation combined oral contraceptives, using the German MediPlus database of patient records. Women studied included 42 patients between the ages of 18 and 49 years, with a diagnosis of VTE treated with an anticoagulant, who were exposed to an oral contraceptive (OC). Four controls per patient (168), matched by year of birth and exposure to an OC on the even day, were identified. More women were users of second generation than third generation OC, and none were using progestogen-only pills. There was no significant difference between patients and control subjects with respect to the type of OC used on the event day (unadjusted odds ratio for third versus second generation users was 0.77; 95% confidence interval [CI] 0.38-1.57). There was no significant age difference between second and third generation users among patients or control subjects. Between January 1 and the event date, there was no significant difference between the patients and control subjects in terms of the number of oral contraceptive prescriptions, number of consultations for psychotherapeutic complaints, or mixed physical and psychotherapeutic consultations; however, patients did demonstrate significantly more consultations for purely physical complaints compared with control subjects (p < 0.0001). There were no significant consultation differences between patients with pulmonary emboli (n = 6) and other VTE patients (n = 36). No significant differences with respect to VTE risk between users of second and third generation oral contraceptives were found in this study. Consultations (physical) for patients were higher than for control subjects before the VTE event. If consultation rate relates to the general health status of a person, this might indicate that VTE risk is higher among women of poorer health, but that this is not related to the type of progestogen in the oral contraceptive that they use.

Norplant consensus statement and background review

This review has highlighted the attributes of a very important new method of contraception. The signatories to this document agree that, with the provision of appropriate information and instruction for the user, Norplant is a good contraceptive choice to be made available worldwide in family planning programs that have the resources for appropriate training and counseling. The signatories to this document are acting in their own personal capacity and not as representatives of any particular organization.

Levonorgestrel-releasing intrauterine device-wearing women express contraceptive glycodelin A in endometrium during midcycle: another contraceptive mechanism?

Intrauterine devices (IUDs) exert contraceptive action by interfering with sperm transport, ovum development, fertilization and implantation. Glycodelin A (GdA) is a uterine glycoprotein that has local contraceptive activity by inhibiting sperm-egg binding. GdA is normally absent from endometrium during the fertile midcycle and it is not expressed until the fifth postovulatory day. The phase of menstrual cycle addressed in this study covers the phase when conception is most likely to follow an unprotected intercourse and when GdA is normally absent. We present here evidence that levonorgestrel-releasing IUD (LNg-IUD) is accompanied by 'inappropriate' expression of GdA in endometrium between days 7 and 16 of the menstrual cycle (six out of six cases). The same was also found in copper-releasing IUD (Cu-IUD)-wearing women, but less frequently (four out of 11 cases, P < 0.0345, Fisher's exact test). In-situ hybridization localized GdA mRNA into endometrial glands in the midcycle endometrium, confirming the cellular site of synthesis. Based on the potent inhibitory activity of GdA on sperm-egg binding, the presence of GdA in uterine glands of IUD wearers may lead to prior exposure of sperm to contraceptive GdA, thus contributing to the contraceptive activity of the IUD.

A multicenter, uncontrolled clinical investigation of the contraceptive efficacy, cycle control, and safety of a new low dose oral contraceptive containing 20 micrograms ethinyl estradiol and 100 micrograms levonorgestrel over six treatment cycles

The aim of the trial was to demonstrate the contraceptive efficacy of a new low dose oral contraceptive containing 20 micrograms ethinyl estradiol and 100 micrograms levonorgestrel and to observe cycle control and safety. Data from 805 treated women resulted in 4400 treatment cycles. One pregnancy occurred while on the trial medication as a result of method failure, resulting in a Pearl index of 0.29. Cycle control was good, and cycle length as well as duration and intensity of withdrawal bleeding were not significantly changed during the trial. Intermenstrual bleeding usually occurred as spotting and decreased considerably during the treatment phase. Spotting alone was reported in 12.4% of cycles, breakthrough bleeding alone in 4.5% of cycles, and breakthrough bleeding and spotting together in 1.4% of treatment cycles. The rate of absence of withdrawal bleeding declined throughout the trial to 2.4% in cycle 6. There were no serious adverse events related to treatment, and most adverse events were those commonly observed in clinical trials with oral contraceptives. Headache, breast tension, and nausea were reported by 17.3%, 11.0%, and 7.7% of the women, respectively. There were no clinically relevant changes in laboratory parameters, blood pressure, or weight. In this trial, the new low dose oral contraceptive containing 20 micrograms ethinyl estradiol and 100 micrograms levonorgestrel was shown to be effective, safe, and well tolerated. Cycle control was found to be good and there was a low incidence of adverse events.

First week drug concentrations in women with levonorgestrel rod or Norplant capsule implants

Forty-two healthy women volunteered to have blood samples drawn at 2, 4, 8, 24, 48, and 168 h (7 days) following placement of levonorgestrel-releasing rod (LNG rod) or of Norplant capsule implants to permit measurement of drug concentrations. Three clinics recruited 10 women each, half of whom used each type of implant. Twelve additional subjects were later enrolled at one site to provide greater detail for the capsule implants. Throughout the week, women with Norplant implants had apparently higher mean drug concentrations than did women with LNG rod implants, but the differences were significant only in the first 48 h after placement (p < 0.05). Maximum levels for capsule implants were found at the 24-h sample (mean, 1358 to 1474 pg/mL) and for the LNG rod implants at 48 h (772 pg/mL). Body weight was negatively correlated with levonorgestrel concentrations at all times (p < 0.05). For several sampling times, differences between clinics in mean concentrations were statistically significant after weight adjustment. Despite differences by implant type, weight, or clinic location, drug concentrations compatible with contraceptive effect were attained within 24 h in users of LNG rod or of Norplant implants, insofar as all women had levonorgestrel concentrations above 250 pg/mL at the 24-h sample.

Use of norethisterone and estradiol in mini doses as a contraceptive in the male. Efficacy studies in the adult male bonnet monkey (Macaca radiata)

Administration of norethisterone (NET) or NET + estradiol benzoate using an Alzet minipump or as once-a-month intramuscular injection of their depot forms, NET-enanthate (NET-EN) and estradiol valerate (E-val), resulted in azoospermia in all monkeys (n = 13) within 60 to 150 days of treatment. Although addition of depot form of testosterone (T, 20 mg/month) to the regimen restored the behavioral response typical of a normal male, it did not reverse the azoospermic state. Serum T (heightened nocturnal) levels were significantly reduced (> 85%, p < 0.001) in all the treated groups. Evidence for blockade in spermatogenesis following treatment was obtained by DNA flow cytometry. Following withdrawal of treatment, the T level was restored to normalcy within 15 days but 120 days more were required for the animals to exhibit normal sperm counts. In conclusion, the efficacy of once-a-month injection of relatively low doses of NET-EN + E-Val to bring about azoospermia in monkeys, in a relatively short time, has been demonstrated. As the results are uniform and reproducible, it appears desirable that this steroid regimen be tested in man for its contraceptive efficacy.

Modern oral contraceptives and cardiovascular disease

We reviewed evidence that bears on the cardiovascular safety of combined oral contraceptives containing second- and third-generation progestogens and < 50 micrograms of estrogen. Recent epidemiologic studies indicate that current use of these formulations is associated with a smaller increase in the incidence of venous thromboembolism than earlier formulations. In some studies the increase for third-generation formulations containing desogestrel or gestodene was about 1.5 to 2 times that for second-generation formulations, but there is evidence that differences between users in underlying risk and likelihood of being diagnosed contributed to this result. Recent studies of myocardial infarction suggest a smaller increase in risk associated with modern formulations than with earlier ones; one study suggests a threefold increase for second-generation formulations and no increase for third-generation formulations, but the finding requires confirmation. Recent studies of stroke indicate little or no increase in risk for modern formulations among women without risk factors. We conclude that modern combined oral contraceptives are safer than earlier formulations with respect to cardiovascular disease, which occurs rarely in young women.

The use of oral contraceptives and the occurrence of acute myocardial infarction in young women. Results from the Transnational Study on Oral Contraceptives and the Health of Young Women

The objective of this study was to assess the risk of myocardial infarction (MI) associated with the use of new and old combination oral contraceptives (OC). A matched case-control study in 16 centers in Germany, the United Kingdom, France, Austria, and Switzerland explored the association of current use of combination OC with the occurrence of MI. Our subjects were 182 women aged 16-44 years with MI; the controls were 635 women without MI (at least one hospital control and one community control per case) matched for 5-year age group and region. The main outcome measures were odds ratios comparing current use of a specific group of OC against current use of other groups or against no current use. The adjusted overall odds ratio (OR; 95% confidence intervals) for MI for second generation OC versus no current use was 2.35 (1.42 to 3.89) and 0.82 (0.29 to 2.31) for third generation OC (low dose ethinyl estradiol, gestodene, and desogestrel). A direct comparison of third generation users with second generation users yielded an OR of 0.28 (0.09 to 0.86). In subgroup analyses, the odds ratio for the UK alone was 1.25 (0.36 to 4.29), while for continental Europe it was 0.10 (0.02 to 0.48). For hospital controls, the risk estimated was 0.98 (0.22 to 4.44), and 0.18 (0.04 to 0.65) for community controls. The independent risk of MI among current smokers adjusted for OC use was 7.21 (4.58 to 11.36). Among users of third generation OC, the OR for current smokers was 3.75 (0.65 to 21.74) and among users of second generation it was 9.50 (2.93 to 30.96). A comparison of OC use in the UK for the time before and after regulatory action was taken in October 1995 shows that the likelihood of a control (last control accrued June 1996) being treated with second generation OC is seven times higher after 1 November 1995 than it was before. Third generation OC are the first to be associated with no excess risk of MI. A significantly lower risk of MI is found when comparing use of third generation OC with use of second generation OC. There seems to be an impressive amelioration of risk among smokers using newer OC. An impact of regulatory action in the UK was found in the OC use spectrum of controls.

The effect of a desogestrel-containing oral contraceptive on glucose tolerance and leptin concentrations in hyperandrogenic women

Ovarian hyperandrogenism can be associated with insulin resistance, hyperinsulinemia, glucose intolerance, and obesity. High levels of the lipostatic hormone, leptin, have also been reported in this condition. The purpose of the present study was to examine the effect of an oral contraceptive (OC) of low androgenicity containing desogestrel on glucose tolerance in hyperandrogenic women and the impact of changes in androgenic/estrogenic status on leptin concentrations. Sixteen nondiabetic hyperandrogenic women, aged 29 +/- 1 yr with a body mass index (BMI) of 36.8 +/- 1.8 kg/m2, underwent an oral glucose tolerance test before and after 6 months of therapy with the OC. Free testosterone decreased and sex hormone-binding globulin increased after therapy (P < 0.001). Glucose tolerance deteriorated significantly, and two women developed diabetes. Body weight, BMI, and leptin did not change significantly. Leptin correlated with BMI before (r = 0.56; P = 0.02) and after (r = 0.51; P = 0.04) treatment, but not with glucose, insulin, total and free testosterone, or sex hormone-binding globulin before or after treatment. In conclusion, 1) glucose tolerance should be monitored in hyperandrogenic women using OC, even those of low androgenicity; and 2) changes in androgenic/estrogenic status had no effect on the leptin concentration, suggesting that its sexual dimorphism is not related to sex steroids.

Treatment of adenomyosis-associated menorrhagia with a levonorgestrel-releasing intrauterine device

OBJECTIVE

To evaluate the efficacy and tolerability of treatment with a levonorgestrel-releasing intrauterine device (IUD) in women affected by adenomyosis-associated menorrhagia.

SETTING

Tertiary care center.

DESIGN

Prospective, open, noncomparative study.

PATIENT(S)

Twenty-five women aged 38 to 45 years with recurrent menorrhagia associated with adenomyosis diagnosed at transvaginal ultrasonography participated in this study.

INTERVENTION(S)

An IUD releasing levonorgestel 20 mcg/day was inserted in each patient within 7 days of the start of menstrual flow. All of the patients were requested to compile a pictorial blood loss assessment chart each month. They underwent clinical and transvaginal ultrasound examinations 3, 6, and 12 months after IUD insertion.

MAIN OUTCOME MEASURE(S)

Menstrual pattern; serum hemoglobin, ferritin, and iron level changes.

RESULT(S)

One patient experienced IUD expulsion 2 months after device insertion and another requested removal of the IUD 4 months after insertion because of persistent irregular blood loss. Six months after IUD insertion, amenorrhea was observed in 2 patients and oligomenorrhea in another, spotting occurred occasionally in 7, and 13 had scanty but regular flow. One year of follow-up has been completed by the remaining 23 women: 2 with amenorrhea, 3 with oligomenorrhea, 2 with spotting, and 16 with regular flows. Significant increases in hemoglobin, hematocrit, and serum ferritin have been observed, but the lipid metabolism and clotting variables have remained unchanged.

CONCLUSION(S)

Our findings indicate that marked and safe relief from adenomyosis-associated menorrhagia can be obtained with the use of a levonorgestrel-releasing IUD.

Return of fertility after discontinuation of the once-a-month injectable contraceptive Cyclofem

The objective of this study was to evaluate the return of fertility in women who used Cyclofem as a contraceptive method during the introductory studies conducted in Brazil, Chile, Colombia, and Peru. From these four cohorts, 101 women were eligible for the study. Thirty-one were not included in the study either because they refused to be interviewed, had initiated another contraceptive method the month after discontinuation, or were unable to be contacted. A total of 70 women were included in the study. Our results showed that the return to fertility rate after the discontinuation of Cyclofem was 1.4 per 100 women at the end of the first month and reached 82.9 at one year. More than 50% were pregnant at 6 months. Fifty-one (94.4%) pregnancies ended in a live birth, two were spontaneous first trimester abortions, and one was a hydatidiform mole. Return of fertility was not related to the woman's age at the time of discontinuation, her weight, or the number of Cyclofem injections. In conclusion, fertility is restored by 1 month following Cyclofem discontinuation. Users and potential users should be counseled regarding the rapid return of fertility after discontinuing this method of contraception.

Effect of topiramate on the pharmacokinetics of an oral contraceptive containing norethindrone and ethinyl estradiol in patients with epilepsy

PURPOSE

Because enzyme-inducing antiepileptic drugs (AEDs) can affect pharmacokinetics of oral contraceptives and thereby cause contraceptive failure, the potential effect of topiramate, a new AED, on the pharmacokinetics of the combination oral contraceptive norethindrone/ethinyl estradiol was evaluated.

METHODS

Twelve women receiving stable valproic acid (VPA) monotherapy for epilepsy received a combination norethindrone 1.0 mg/ethinyl estradiol 35-microg tablet daily for 21 days followed by seven daily doses of inert tablets for four 28-day cycles. After a baseline cycle (cycle 1), topiramate 100, 200, and 400 mg every 12 h was administered in cycles 2 through 4, respectively. Serial blood samples were obtained on day 20 of each cycle and were analyzed for norethindrone, ethinyl estradiol, and progesterone by using validated radioimmunoassay methods.

RESULTS

Compared with cycle 1, none of the norethindrone pharmacokinetic parameters changed significantly in the presence of topiramate, 100-400 mg every 12 h. Individual patient serum progesterone concentrations measured during each cycle were at or close to the limit of quantification with no apparent differences among cycles. However, mean area under the concentration-versus-time curve over the 24-h period (AUC(0-24)) values for ethinyl estradiol were 18-30% lower in cycles 2 through 4 compared with cycle 1 (p < or = 0.05 for all pairs), whereas mean oral serum clearance (CL/F) values were 14.7-33.0% higher (p < or = 0.05 for cycles 2 and 4 vs. cycle 1). Mean time of peak concentration (T(max)) values determined during topiramate therapy were not significantly different from those at baseline.

CONCLUSIONS

When prescribing an oral contraceptive for patients receiving topiramate, clinicians should consider initial therapy with an agent containing > or = 35 microg of ethinyl estradiol.

Contraceptive efficacy, pharmacokinetics, and safety of Annuelle biodegradable norethindrone pellet implants

OBJECTIVE

To evaluate the contraceptive efficacy, pharmacokinetics, and safety of two formulations of Annuelle (Endocon, Inc., South Walpole, MA) biodegradable norethindrone (NET) SC pellet implants.

DESIGN

Prospective observational study.

SETTING

Two clinical sites in the United States.

PATIENT(S)

Thirty-nine healthy, fertile, sexually active women.

INTERVENTION(S)

Nineteen women received a four-pellet system containing 174 mg NET; 20 women received a five-pellet system containing 266.5 mg NET.

MAIN OUTCOME MEASURE(S)

Contraceptive efficacy, median serum NET levels, adverse events.

RESULT(S)

No pregnancies were observed in 293 woman-months in the four-pellet group or in 375 woman-months in the five-pellet group. An initial burst in median serum NET levels occurred in the first 24 hours postinsertion followed by a steady decline over the next 3 years. Norethindrone levels varied considerably among women. The main side effect was bleeding abnormalities, which persisted in half the participants for up to 2 years. No serious adverse events were reported that were related to the pellets. Pellet insertion and removal generally were uncomplicated.

CONCLUSION(S)

Annuelle shows potential as an effective, safe contraceptive with distinct advantages over other long-acting agents, because it is biodegradable but can be removed if problems arise or if fertility is desired.

The pharmacodynamic effects of an oral contraceptive containing 3 mg micronized 17 beta-estradiol and 0.150 mg desogestrel for 21 days, followed by 0.030 mg desogestrel only for 7 days

During oral treatment with 3 mg micronized 17 beta-estradiol and 0.150 mg desogestrel for 21 days followed by 0.030 mg (A) desogestrel (15 women) or placebo (B) (14 women) for 7 days, ovarian function, bleeding pattern and estradiol levels were evaluated. The study was performed in a group-comparative, double-blind fashion. During a pre-treatment control cycle, using ultrasound scan, follicular diameter was measured on cycle days 10-16 and endometrial thickness on one of cycle days 22-26. Estradiol was measured at the time of ultrasound scan and progesterone three times in the luteal phase. During three treatment cycles, follicular diameter and endometrial thickness were monitored three times weekly and at the same time, estradiol and progesterone were measured. Treatment resulted in anovulation in all women. Maximum and mean estradiol levels were approximately 900 pmol/l and 550 pmol/l during treatment, respectively, and approximately 200 pmol/l during the estradiol-free weeks in both groups. Ten women showed ovarian activity (follicle size > or = 15 mm) during treatment, seven in group A and three in group B. Endometrial thickness decreased approximately 3 mm during treatment in both groups. The incidence of breakthrough bleeding and spotting was higher in group A when compared to group B. The study indicates that the combination of 3.0 mg micronized estradiol and 0.150 mg desogestrel is an effective and safe contraceptive, offering an acceptable cycle control. The addition of a low dose of desogestrel during the pill-free period did not further suppress ovarian activity nor improve the bleeding pattern. The results of this study should be interpreted with great care, since the number of women studied is relatively small.

A risk-benefit assessment of the levonorgestrel-releasing intrauterine system

The levonorgestrel-releasing intrauterine system (LNG-IUS), has been developed by Leiras Pharmaceuticals, Turku, Finland. It is a new systemic hormonal contraceptive that releases levonorgestrel 20 micrograms every 24 hours. The device provides fertility control comparable with that of female sterilisation, complete reversibility and convenience, and has an excellent tolerability record. The low dosage of levonorgestrel released by its unique delivery system ensures minimal hormone-related systemic adverse effects, which tend to be in the category of 'nuisance' rather than hazardous, and gradually diminish after the first few months of use. In some respects, the contraceptive characteristics of the LNG-IUS have over-shadowed a substantial range of noncontraceptive beneficial effects that are rarely seen with inert or copper-releasing intrauterine contraceptive devices (IUDs), and have important and positive gynaecological and public health implications. This applies particularly to the profound reduction in duration and quantity of menstrual bleeding, and alleviation of dysmenorrhoea, which are associated with the use of the device. Recent studies have shown that the LNG-IUS is effective in preventing endometrial proliferation associated with oral or transdermal estradiol therapy, and in inducing regression of endometrial hyperplasia. Further research is required to determine whether it has a role in regulating the growth of uterine fibroids, and preventing pelvic inflammatory disease. The unique unwanted noncontraceptive effects of the system, including possible development of functional ovarian cysts, and the relationship between menstrual bleeding pattern and ovarian function, also require better understanding, in order to offer appropriate patient counselling and maximise acceptability and continuation of use of the method.