Omitting the first oral contraceptive pills of the cycle does not automatically lead to ovulation

OBJECTIVE

Our purpose was to test the hypothesis that omitting the first three pills of the contraceptive cycle leads to ovulation.

STUDY DESIGN

Ninety-nine women, randomly assigned to 1 of 3 treatments of combined oral contraceptives, completed the study. Treatments contained ethinyl estradiol and either monophasic gestodene, triphasic gestodene, or monophasic desogestrel. Pituitary-ovarian activity was monitored by ultrasonography of the ovaries and assay of serum concentrations of estradiol, progesterone, and follicle-stimulating hormone over 1 normal cycle (study period 1) and 1 cycle after an extended pill-free interval of 10 days (study period 2).

RESULTS

None of the women experienced normal ovulation as evaluated by ultrasonography and serum progesterone concentrations. However, follicle-stimulating hormone reached a maximal serum concentration in most women during the first 7 pill-free days, indicating complete pituitary recovery, and increases in serum estradiol concentrations were seen in each woman although with marked interindividual variation. During study period 2 we found follicles of >18 mm in 24%, 24%, and 40% of the monophasic gestodene, triphasic gestodene, and monophasic desogestrel groups, respectively.

CONCLUSIONS

Follicular growth up to preovulatory size is common in women missing the first one to three pills of their contraceptive cycle. Although this creates the prerequisite for ovulation, normal ovulation did not occur when pill omissions were limited to only 3 days.

A regimen of oral contraceptives restricted to the periovulatory period may permit folliculogenesis but inhibit ovulation

Increased safety of oral contraceptives (OC) has resulted from a reduction in the estrogen and progestin content per tablet. A reduction in the number of hormonally active pills and their placement at critical points within the cycle may provide a novel regimen for further reducing the hormonal content of OC per cycle and their attendant side effects without compromising efficacy. The objective of this study was to determine the effectiveness of two OC regimens that incorporate a delayed start and limited midcycle use of the combination of ethinyl estradiol and norethindrone, and limited use of norethindrone only during the second half of the cycle. Main outcome measures were defined as ovulation, serum concentrations of estradiol (E2), luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (P), follicular diameters, and endometrial thickness. Volunteers were issued blister packs containing 28 pills and randomized to one of two groups. Group 1 used a combination of 50 micrograms ethinyl estradiol and 1 mg norethindrone per tablet day 6-10, and 0.70 mg norethindrone only day 11-19. Placebo tablets were used on days 1-5 and day 20-28. Group 2 used a combination of 50 micrograms ethinyl estradiol and 1 mg norethindrone per tablet on day 8-12, and 0.70 mg norethindrone only on day 13-21. Placebo tablets were used on day 1-7 and day 22-28. A total of 20 cycles were studied using 10 volunteers. To assess any possible carryover effect, two successive cycles were studied for each subject. Serum sampling for E2, FSH, LH, and P, and transvaginal ultrasound imaging to assess endometrial thickness and follicle diameter were carried out at 4 day intervals throughout the cycle. One ovulation occurred in 10 cycles in group 1. Five ovulations occurred in 10 cycles in group 2. All ovulations, regardless of group, occurred in the second cycle. Peak E2 concentrations were not significantly different between groups (152.04 +/- 107.1 pg/mL vs 162.1 +/- 56.1 pg/mL [mean +/- SD] for groups 1 and 2, respectively] but occurred earlier in the cycle in group 1. No differences were noted between the groups in serum concentrations of FSH or LH for any given cycle day. Maximum follicle diameters were not different between groups 1 and 2, regardless of ovulatory status (20.5 +/- 8.1 mm2 vs 20.6 +/- 14.2 mm2, respectively). Ultrasound imaging assessment of midcycle follicle growth revealed diameters ranging from 18.5 mm2 to 34.0 mm2 with gradual resolution through the second half of the cycle in anovulatory cycles, and 16.0 mm2 to 23.5 mm2 with abrupt disappearance in ovulatory cycles. Endometrial thickness did not exceed 10 mm for any anovulatory cycle regardless of group, but ranged from 6 to 9 and 6 to 11 during the luteal phase of ovulatory cycles of groups 1 and 2, respectively. Peak serum P concentrations at midluteal phase in ovulatory cycles ranged from 9.2 ng/ml to 18.2 ng/ml. Data from this preliminary study suggest that ovulation may be prevented with a combination of ethinyl estradiol and norethindrone started as late as cycle day 6 and limited to 5 days' duration using norethindrone only for 9 days during the second half of the cycle. Such a restricted regimen may offer both an effective method of contraception and a means of further reducing both estrogen and progestin content per cycle and the possible short and long term adverse side effects of these hormones.

The 1995 pill scare revisited: anatomy of a non-epidemic

Two years after the October 1995 pill scare that received worldwide attention, this synthesis of evidence goes back to the earliest research on risks of first generation oral contraceptives (OCs). It also covers epidemiological data published since, emphasising the 1995-1996 findings. Late breaking data are also examined. The key issue: are there differences in the risk profiles of second and third generation OCs. The ultimate question is: did any epidemics of venous thromboembolism (VTE) occur? This synthesis of evidence leads to the following conclusions and observations: (i) all OCs on the market are becoming progressively safer; (ii) relative risks of about 2 for VTE, even if real, are clinically unimportant and of no public health significance; (iii) the weak odds ratios contrasting third and second generation OCs, ranging from 1.5 to 2.3 in the 1995-1996 studies are more likely explained by bias than by a causal relationship; (iv) incidences of VTE among users of any OC have been declining over the past three decades; (v) absolute rates of VTE for third generation OC users reported in 1995-1996 are lower than those for users of second generation OCs in 1988 and 1991; (vi) there is no difference in risk of VTE between first starters on second generation OCs versus first starters on third generation OCs; (vii) users of third generation OCs are at much lower risk of acute myocardial infarction than users of second generation OCs; (viii) among users of any OC, the occurrence rates of stroke are low, they are declining, and no differences between second and third generation OCs are apparent; (ix) 2 years after the pill scare there are no epidemics of VTE; (x) there have been excessive rates of therapeutic abortions in some countries; and (xi) the benefit-risk ratio is favourable for users of any OC.

Haemostatic changes and the oral contraceptive pill

Oral contraceptives have been linked to an increased incidence of thrombovascular disease. This may be mediated by their effects on the haemostatic system. An increase in the activity of coagulation Factors VII, X and fibrinogen occur with pill usage. Increased Factor VII levels are dependent on both the oestrogen and progestogen component of the oral contraceptive. A reduction in antithrombin III levels has also been observed in some but not all studies. Increased fibrinolysis has also been shown in oral contraceptive users which should balance the changes in the coagulation pathway. The increase in fibrinolytic potential is thought to be due to a decrease in the levels of plasminogen activator inhibitor I combined with an increase in the levels of plasminogen; tissue plasminogen activator antigen is decreased in most studies. The increased levels of endpoints of coagulation and fibrinolysis in pill users indicate that enhanced activity of both systems is occurring in vivo. The increased coagulation activity appears to be balanced by the rise in fibrinolytic activity, so preserving haemostatic balance. Enhanced platelet activity has also been shown in women taking oral contraceptives. Thrombus formation can result, however, when local vascular wall damage exists, or when other risk factors for thrombo-embolism, such as older age and smoking, coexist and create a local activation resulting in a thrombus. In these situations, the small differences in levels of coagulation factors in women taking different oral contraceptive formulations may be important. Pills containing the lowest doses of oestrogen (20 micrograms ethinyloestradiol) have shown the least changes in haemostatic factors. The progestogen component of the pill modifies the effect of oestrogen on the haemostatic system.

The pill and thrombosis: epidemiological considerations

The oral contraceptive is one of the most widely taken medications in the healthy population. The clinically important side-effects are venous and arterial thrombosis. Accurate estimates of incidence of these side-effects have proven to be difficult. Diagnostic modalities for thrombosis are sub-optimal and the problems of study methodology, primarily a reliance on non-experimental studies, have limited the ability to define the attributable risk of thrombosis from oral contraception. Pharmacological attempts to further decrease venous thrombotic side-effects by the use of third-generation oral contraceptives have failed. This places a greater emphasis on the selection of patients to help avoid giving medication to those patients with underlying thrombotic risk factors. An example of this approach has been the clear confirmation of the adverse effects of cigarette smoking and arterial thrombosis in oral contraceptive users. At the biochemical level, hypercoagulability testing may be useful. Screening for high-frequency prothrombotic abnormalities, such as the Factor V Leiden genotype, represents an important addition to the process by which patients are selected, and may be prototypic of further advances.

Modulation of ovarian function by an oral contraceptive containing 30 micrograms ethinyl estradiol in combination with 2.00 mg dienogest

Twenty-two healthy female volunteers with normal ovulatory cycles, aged between 20 and 34 years (27.3 +/- 4.1), were included in a single-center, noncomparative study to investigate the modulation of ovarian function by an oral contraceptive containing 30 micrograms ethinyl estradiol in combination with 2.00 mg dienogest. At baseline, during three treatment cycles and post-treatment, serum levels of luteinizing hormone, follicle-stimulating hormone, 17 beta-estradiol, and progesterone were assayed and ultrasonography was used to measure follicular size and the thickness of the endometrium. The primary efficacy variable was inhibition of ovulation as measured by ovarian activity grading. All volunteers ovulated during the pretreatment cycle. During treatment, none of the subjects had ovulatory cycles, although there was still some ovarian activity in several subjects. During the first treatment cycle, only 4% (1 subject) of cycles showed active follicle-like structures. The frequency of follicle-like structures increased to 33% and 35% during treatment cycles 2 and 3. The frequency of presumptive luteinized unruptured follicle-like structures was 5% (1 subject) and 15% (3 subjects) in treatment cycles 2 and 3. The serum hormone concentrations were effectively suppressed in comparison to baseline. The ovarian activity returned to baseline during the post-treatment period. One subject was excluded from further study because of a medical problem believed unrelated to use of the oral contraceptive. No serious adverse events were recorded during the course of the study. The results of the present investigation indicate that the modulatory effects on ovarian function of the monophasic oral-contraceptive containing 30 micrograms ethinyl estradiol combined with 2.00 mg dienogest lead to adequate suppression of ovarian activity and effective inhibition of ovulation.

Bone mass and long-term monophasic oral contraceptive treatment in young women

A prospective study has been designed to investigate bone metabolism in young women taking an oral monophasic contraceptive formulation (ethinylestradiol 20 micrograms + desogestrel 0.150 mg) over 5 years. Healthy women (n = 200) between 19 and 22 years of age were divided into two groups. Group A received oral contraception, Group B did not receive any treatment. All the subjects underwent a bone mass density (BMD) evaluation at spinal level L2-L4 with Dexa (Norland XR-26) and a measurement of the serum alkaline phosphatase levels and urinary excretion of OH-proline at baseline and every 12 months over 5 years. Our results demonstrated that Group A did not show any significant BMD change after 5 years of oral contraceptive treatment, while Group B demonstrated a significant increase (p < 0.01) in the bone mass content at the end of the time of observation (+7.8% after 5 years). No significant changes were found in serum alkaline phosphatase levels and in urinary excretion of OH-proline at the end of the study in comparison with basal levels in both groups. Our data suggested that long-term treatment with an oral monophasic contraceptive formulation (ethinylestradiol 20 micrograms + desogestrel 0.150 mg) did not modify the BMD but prevented the occurrence of the physiologic peak of bone mass in young women.

A two-year clinical study of the effects of two triphasic oral contraceptives on plasma lipids

OBJECTIVE

Oral contraceptive formulations can alter plasma lipid and lipoprotein levels; however, lower-dose triphasic tablets show only minimal metabolic effects during 6 or 12 cycles of use. Involvement of lipids in chronic cardiovascular conditions, plus long-term use of oral contraceptive tablets, prompted this first 24-cycle study of the effect of triphasic formulations on young women.

METHODS

69 women assigned randomly to an ethinyl estradiol/levonorgestrel formulation (Triphasil) or an ethinyl estradiol/norethindrone formulation (Ortho 7/7/7) and 25 control women (no hormonal contraception) had blood sampled for lipids and lipoproteins pre-trial, and at 3- or 6-cycle intervals for 24 cycles.

RESULTS

At cycle 24, control women experienced no significant change from baseline in any variable except apolipoprotein B (apo B). Plasma apo B increased 42% (P < .01), reflecting the LDL apo B increase (42%, P < .01). Both combination formulations significantly increased apo B (plasma, VLDL, IDL and LDL); the increases ranged between 47% and 84%. Plasma apo A1 rose (15%, P < .001) in the Ortho 7/7/7 group only. Plasma and LDL triglycerides were increased significantly (P < .001) by the norethindrone product, 43% and 81%, respectively, and plasma and LDL cholesterol, 14% and 28%, respectively. Cholesterol decreased in all other subfractions, including HDL (11%, P < .01). HDL cholesterol decreased significantly in the Triphasil group (8%, P < .05); no other cholesterol subfractions changed significantly. All cycle-24 lipid and lipoprotein values remained well within respective normal ranges.

CONCLUSION

Although 2-year exposure to the triphasic oral contraceptive formulations changed the lipid risk factors for cardiovascular disease only within normal ranges, there remains potential for long-term health effects when compounded with other risk factors.

Sex hormone receptor binding, progestin selectivity, and the new oral contraceptives

The desired biologic effect of progestins used in OCs is progestational activity. Undesired pharmacologic properties such as androgenic activity are not necessary for contraception and increase the potential for adverse effects. A selective progestin has progestational effects at relatively low concentrations or doses and androgenic effects at only relatively high concentrations or doses. The degree to which progestational activity is maximized and androgenic activity is minimized is a measure of a progestin's selectivity. The ratio of its affinity for progesterone receptors to its affinity for androgen receptors is the selectivity index. To minimize the androgenic side effects associated with the older progestins, the doses used in OCs have been reduced over the years. These dose reductions have decreased the potential for undesired androgenic effects but also have negatively affected cycle control. Three new progestins, norgestimate, desogestrel, and gestodene, have relatively greater affinity for progesterone receptors than for androgen receptors when compared with the older agents, permitting a reduction in androgenic side effects without the need for further dose reduction. Preclinical receptor-binding studies and animal pharmacologic studies have documented the higher selectivity indexes of these new progestins. Their higher ratios of progestational to androgenic activity provide the basis for the reduction in androgenic adverse effects observed with their clinical use.

Systemic availability of levonorgestrel after single oral administration of a norgestimate-containing combination oral contraceptive to 12 young women

Norgestimate is a novel progestin which undergoes both in vivo and in vitro metabolic conversions to a number of metabolites, of which the most important are levonorgestrel acetate, levonorgestrel oxime and levonorgestrel itself. It has been claimed that the progestogenic activity of norgestimate in clinical studies is almost exclusively based on the parent drug and its major metabolite, levonorgestrel oxime, and that levonorgestrel does not make an important contribution. However, to date, no data on the presence of levonorgestrel in the serum of women who have received oral doses of norgestimate have been presented. In the present study, 12 young female volunteers received single oral doses of 250 micrograms levonorgestrel in combination with 50 micrograms ethinylestradiol and 250 micrograms norgestimate in combination with 35 micrograms ethinylestradiol in an open, randomized, intraindividual comparison. Blood samples were taken at regular time intervals after each treatment, and the serum samples were analyzed for their content of levonorgestrel. Basic pharmacokinetic parameters of levonorgestrel were calculated and from the ratio of the AUC values obtained after both administrations, the bioavailability of norgestimate-derived levonorgestrel was calculated. About 22 +/- 6% of the dose of norgestimate administered became systemically available as levonorgestrel. Thus, it was concluded that levonorgestrel is a major metabolite of orally administered norgestimate, and that at least part of the pharmacologic activity of norgestimate in women is due to the presence of levonorgestrel.

Comparison of two triphasic oral contraceptives containing either gestodene or norethindrone: a randomized, controlled trial

Two triphasic oral contraceptives containing either gestodene or norethindrone as the progestogenic compound combined with ethinyl estradiol were compared in a randomized clinical trial to assess their contraceptive reliability, clinical tolerance and cycle control. Both preparations were effective in preventing pregnancy. The gestodene preparation proved significantly superior regarding cycle control and general tolerance.

Hemostatic and metabolic effects of lowering the ethinyl-estradiol dose from 30 mcg to 20 mcg in oral contraceptives containing desogestrel

The metabolic and hemostatic effects of two oral contraceptives containing 150 mcg desogestrel and 20 mcg ethinyl-estradiol (EE) (MERCILON) or 30 mcg EE (MARVELON) were compared in order to examine the effect of reducing the EE dose in contraceptive pills. Forty-nine women participated in this randomized study during 6 cycles. In both groups, there was a significant increase in triglycerides, HDL-cholesterol and apoprotein A1; the same increase was observed for SBP and CBG. Slight and transient variations of fasting blood glucose levels were seen in the 30 mcg EE group and in the two groups for fasting insulin levels. The increase in renin substrate was significantly higher with the 30 mcg EE than with the 20 mcg EE pill. In both groups, plasminogen increased significantly, but antithrombin III, total and free protein S and fibrinogen decreased significantly only in women taking the 30 mcg EE pill, whereas there was no significant change in the 20 mcg EE group. Reducing the dose of EE in oral contraceptives from 30 mcg to 20 mcg minimizes their impact on renin substrate and hemostatic parameters.

Comparative study on the efficacy and acceptability of two contraceptive pills administered by the vaginal route: an international multicenter clinical trial

The efficacy and acceptability of two widely used oral contraceptive tablets, one containing 250 mg levonorgestrel and 50 micrograms ethinyl estradiol and the other containing 150 micrograms desogestrel and 30 micrograms ethinyl estradiol, administered by the vaginal route were compared in 1055 women studied over 12,630 woman-months of vaginal contraceptive pill use. This multicenter clinical trial was performed in nine countries of the developing world by the "South to South Cooperation in Reproductive Health," an organization founded by scientists from the Third World working in the area of reproductive health, and the study was developed and coordinated by one of these centers. The findings of this study confirm the efficacy of both these tablets when administered by the vaginal route. Involuntary pregnancy rates at 1 year of 2.78 for subjects in the levonorgestrel group and 4.54 for subjects the desogestrel group showed no statistically significant difference between the two groups. However, total discontinuation rates of 47.01 for subjects in the levonorgestrel group and 56.33 for subjects in the desogestrel group showed a statistically significant difference between the two groups, and discontinuation rates attributable to prolonged bleeding of 0.6 for subjects in the levonorgestrel group and 3.2 for subjects in the desogestrel group were also significantly higher in the group of subjects using the desogestrel vaginal contraceptive pill. Blood pressure remained at admission values throughout treatment. A statistically significant weight increase from admission values occurred in both groups of subjects.

Possible interaction between oxcarbazepine and an oral contraceptive

The effect of oxcarbazepine (OCBZ) on the kinetics of an oral contraceptive containing ethinyloestradiol (EE) and levonorgestrel (LNG) was investigated in 13 healthy female volunteers who had previously received the contraceptive for at least 3 months. After 15 days of the first study cycle, each subject received, in addition to the oral contraceptive, 300 mg OCBZ on day 16, 300 mg twice daily on day 17, and 300 mg three times daily from day 18 of the first cycle to day 18 of the next menstrual cycle. The area under the curve values for both EE and LNG decreased when OCBZ was given with the oral contraceptive (p = 0.006, analysis of variance). The results indicate that OCBZ, like most antiepileptic drugs (AEDs), decreases the bioavailability of EE and LNG, perhaps by affecting metabolism or protein binding.

Interrelationship of serum levonorgestrel and sex hormone-binding globulin levels following vaginal and oral administration of combined steroid contraceptive tablets

Ten women were treated daily with a standard dose contraceptive tablet containing 0.25 mg levonorgestrel (LNG) in combination with 0.05 mg ethinylestradiol. Five women used the tablet vaginally, while the other five used it orally. Blood samples were taken at frequent intervals on the first day of treatment and after 1 and 2 hours on treatment days 7 and 14. Serum LNG levels were measured by radioimmunoassay, and sex hormone-binding globulin (SHBG) was quantitated by charcoal assay. On day 1, peak concentrations of LNG (5.1 ng/ml) occurred within 2 hours in the oral group, whereas in the vaginal group a peak of 2.2 ng/ml was reached after 4 hours. After 24 hours, mean serum concentrations of LNG were 1.1 and 0.69 ng/ml in the oral and vaginal groups, respectively. In both groups, mean LNG concentrations increased dramatically on days 7 and 14 compared to day 1. There was no significant difference between the two groups in LNG concentrations, except after 2 hours on day 1. SHBG levels were increased after one day of treatment. By day 14 of treatment, there was a 3.5- to 4.5-fold rise in SHBG levels from pretreatment values in both groups. However, there was no significant difference in SHBG levels between the two groups throughout the study. A high correlation was found between serum levels of SHBG and LNG in both the vaginal and oral groups. The results suggest that the increase in serum LNG levels in women receiving combined contraceptive tablets either vaginally or orally is due to increased levels of SHBG. Also, the measured concentrations of LNG in the vaginal group are consistent with the previously reported clinical contraceptive efficacy of combined contraceptive tablets administered vaginally.

The acceptance of a 7-week cycle with a modern low-dose oral contraceptive (Minulet)

Cycle control and tolerance were studied in a group of 55 female volunteers, who took during 42 consecutive days a modern low-dose oral contraceptive: gestodene 75 micrograms/ethinylestradiol 30 micrograms (Minulet). During these 42 days, 96% of the women experienced no breakthrough bleeding and 81% of the women experienced no spotting or breakthrough bleeding. When the findings of this study are compared with the findings of an earlier study with also a seven-week cycle but with other oral contraceptives, it can be concluded that Minulet offered an excellent cycle control.

Single and multiple administration of a new triphasic oral contraceptive to women: pharmacokinetics of ethinyl estradiol and free and total testosterone levels in serum

Ethinyl estradiol is part of almost every combined oral contraceptive, and its pharmacokinetic characteristics have been thoroughly investigated in numerous studies. However, little is known about its pharmacokinetics during long-term administration, as compared with single-dose administration. In this study 10 women received a triphasic formulation that contained ethinyl estradiol together with the progestin gestodene over one treatment cycle. Mean area under the curve values of ethinyl estradiol were significantly higher on the last treatment day, as compared with the corresponding values obtained from the same women after single-dose administration. However, the observed increase in area under the curve was within the range of pharmacokinetic accumulation, to be expected on the basis of dosing interval and terminal half-life. Another point of interest was the effect of the triphasic preparation on testosterone concentrations in serum. Both total and free testosterone levels were suppressed by about 60% as compared with pretreatment values, and there was no correlation with corresponding sex hormone-binding globulin levels in the serum.

Ovarian response in superovulated cycles after suppression with oral contraceptive steroids

The endocrine response to controlled ovarian hyperstimulation was reviewed in 94 women undergoing in vitro fertilization during 114 cycles. The purpose of this review was to evaluate the effect of short-term oral contraceptive suppression on the recovery of pituitary gonadotropin function and subsequent controlled ovarian hyperstimulation. Seventy-three cycles (64%) were adequate for oocyte retrieval. In 41 cycles (36%) hyperstimulation was discontinued. The serum 17 beta-estradiol value in women with a poor response was 57 +/- 50 pg/ml on day 8 compared with 376 +/- 334 pg/ml in the women who completed in vitro fertilization (p less than 0.05). The majority of women (84.2%) had a prompt response to controlled ovarian hyperstimulation after short-term oral contraceptive suppression. Most discontinuations were due to dominant follicle selection or luteinizing hormone surge and not to oversuppression by short-term oral contraceptives. Clinical pregnancies occurred in 15 women (20.5% of harvests).

Oral contraceptives stimulate the excretion of clofibric acid glucuronide in women and female rats

1. Glucuronidation of clofibric acid, the pharmacologically active form of the hypolipidemic drug clofibrate was investigated in a human population, either in vitro with liver homogenates from biopsies, or after ingestion of the drug and determination of the urinary metabolite. No difference in the glucuronidation rate according to age of the patients was observed. Bilirubin but not clofibric acid glucuronidation was significantly higher in women (106% increase), when expressed per gram of tissue. 2. The excretion of clofibryl glucuronide in women who took oral contraceptives was significantly enhanced by 25%. 3. In female rats, treatment with the contraceptive agent norethindrone also stimulated by 48% the formation of clofibrylglucuronide in liver microsomes.

Long-term treatment with the combination ethinylestradiol and cyproterone acetate in polycystic ovary syndrome

This study evaluates the effect of therapy over a long period of time (36 cycles without interruption) with the monophasic combination containing 0.035 mg of ethinylestradiol and 2 mg of cyproterone acetate (EE35-CPA) on hormonal and clinical parameters of 66 patients with polycystic ovary syndrome (PCOS). During the administration of the pill a significant decrease in the LH/FSH ratio and in adrenal and ovarian androgens has been observed, as well as a significant increase of the Sex Hormone Binding Globulin (SHBG). The progressive decrease of the total androgenic activity explains the clinical results that have been obtained: at the 36th cycle of therapy acne disappeared in 100% of the cases, seborrea in 76.4% and hirsutism in 75%. Our results underline the need for a continuous administration without interruption of the pill with CPA in patients with clinical hyperandrogenic symptoms.

Gonadotropin and estradiol secretion during the week of placebo therapy in oral contraceptive pill users

The changes in the hypothalamic-pituitary-ovarian axis during the placebo week in oral contraceptive pill users were assessed. Fifteen women using the combined oral contraceptive pill were studied for eight hours at the start and at the end of the placebo week and gonadotropin secretion and estradiol concentrations were compared with those in control women in the follicular phase of an unmedicated menstrual cycle. Both gonadotropin and estradiol concentrations were suppressed at the start of the placebo week. By day 7 of placebo, gonadotropin concentrations and pulse patterns were indistinguishable from those of the control subjects although estradiol concentrations were still significantly lower.

Intra- and interindividual variations in contraceptive steroid levels during 12 treatment cycles: no relation to irregular bleedings

During one year of treatment with oral contraceptives containing 30 micrograms ethinylestradiol and 150 micrograms desogestrel (EE/DG) or 30 micrograms EE and 75 micrograms gestodene (EE/GSD), the serum concentrations of EE, 3-keto-desogestrel (KDG) and GSD were determined on day 1, 10 and 21 of the 1st, 3rd, 6th and 12th cycle. The areas under the time-versus-concentration curves were calculated from the levels before and 0.5, 1, 1.5, 2, 3, 4 and 24 hours after intake of a tablet. There were large intra- and interindividual variations both revealing coefficients of variation (C.V.) between 25% and 80% (EE),, 30% and 50% (KDG) and 30% and 65% (GSD). During each cycle, the EE levels increased significantly between day 1 and 10 by 70% on average reaching a steady-state, while the progestogen concentrations rose by 100% (KDG) and 150% (GSD) up to a steady-state between day 10 and 21. After reaching the steady-state, the C.V. were generally lower. The ratios between the levels of EE and the progestogens showed still higher variations indicating different influences on the estrogen and progestogen component. There was no correlation between the steroid levels and weight, height or age. In spite of the large intraindividual variations, most of the women showed a distinct pattern of the levels of EE and the progestogens throughout the year of treatment indicating a genetic or acquired predisposition. The difference in the average AUC of EE, KDG and GSD between the women was 300% at most. During the first cycle of treatment with EE/DG and EE/GSD, about half of the women recorded intermenstrual bleedings which decreased thereafter. There was no relation between the occurrence of irregular bleedings and the average serum levels of EE and the progestogens of the individual women, neither during the first cycle nor during the whole treatment period of 12 cycles. It is concluded that spottings or breakthrough bleedings during treatment with oral contraceptives are not dependent on a distinct pattern of the serum levels of EE and the progestogen.

Oral contraceptives. Who, which, when, and why?

The risks of oral contraceptives are very small, and they cluster in a subset of users, although warning signs of cardiovascular complications must be heeded. The best choice of an oral contraceptive is one with an estrogen content of 30 to 35 micrograms. A greater (50 micrograms) content may be necessary if breakthrough bleeding or amenorrhea persists beyond a few treatment cycles. The starting date for the pill can be up to the sixth day of the cycle. Noncontraceptive benefits of the pill may include a protective effect against endometrial and ovarian malignancy, benign breast disease, and infection of the upper genital tract. Both the contraceptive and noncontraceptive benefits of low-dose combination oral contraceptives are desirable. They far outweigh the risks in women who require a high-efficacy, reversible contraceptive and who have no significant contraindication to use of the pill.

Development of a low-dose monthly injectable contraceptive system: I. Choice of compounds, dose and administration route

A low-dose combined estrogen-progestogen sustained release system has been developed. The control of crystal size of the steroids produced sustained dissolution in vitro and in vivo. A dose-response experiment carried out in healthy women indicated that 10 mg of norethisterone (NET) with 1 mg of ethinylestradiol (EE2) when given by intramuscular injection maintained NET serum levels above 1 ng/ml for at least 25 days. The system is considered suitable for one month contraceptive protection.

Effects of levonorgestrel and desogestrel in low-dose oral contraceptive combinations on serum lipids, apolipoproteins A-I and B and glycosylated proteins

Fasting serum lipids, apolipoproteins and glycosylated serum proteins were studied in 20 women before, after three months of treatment and two months after termination of treatment with oral contraceptives containing 30 micrograms ethinyloestradiol (EE) plus 150 micrograms levonorgestrel or desogestrel. Levonorgestrel + EE induced significant increases in total triglycerides (48%), apoB (19%) and the ratio apoB/apoA-I (18%) and no significant changes in HDL-cholesterol (8% decrease), apoA-I, % HDL-cholesterol, total cholesterol and serum glycosylated proteins. Desogestrel + EE induced significant increases in HDL-cholesterol (12%), % HDL-cholesterol (15%), triglycerides (35%) and apoA-I (20%), no changes in total cholesterol, apoB and glycosylated serum proteins and a significant decrease in the ratio apoB/apoA-I (17%). Two months after termination of treatment the values for all parameters for both preparations were similar to those observed before treatment. The differences between the effects of the two preparations on the parameters HDL-cholesterol, % HDL-cholesterol, apoA-I, apoB and the ratio apoB/apoA-I were statistically significant and can be explained by a difference in the intrinsic androgenicity of the two progestagens.

Ovulation inhibition following vaginal administration of pills containing norethindrone and mestranol

Plasma levels of estradiol and progesterone were investigated in women using daily vaginal pills containing 1 mg norethindrone and 50 mcg mestranol. Of 13 treatment cycles in ten women using one vaginal pill daily, six were ovulatory and seven anovulatory. All 12 cycles in ten women using two vaginal pills daily were anovulatory.

Effect of estrogen/progestin potency on lipid/lipoprotein cholesterol

We studied 374 women taking oral contraceptives, 284 women taking estrogen preparations after menopause, and 1086 women taking no hormones, to determine the relation of plasma lipids and lipoprotein cholesterol concentrations to various types of estrogen/progestin formulations. Premenopausal women, using oral contraceptives containing a relatively low dose of estrogen combined with a medium or high dose of progestin (Norlestrin, Ovral, or Demulen) had a 24 per cent higher median concentration of low-density-lipoprotein cholesterol than did those not using hormones (P less than 0.05). Women using oral contraceptives that are high in estrogen and low in progestin (Enovid or Oracon) had significantly higher concentrations of high-density-lipoprotein cholesterol than did nonusers; those using Ovral, a low-estrogen and high-progestin formulation, had significantly lower levels of high-density-lipoprotein cholesterol. In postmenopausal women the use of estrogen was associated with concentrations of low-density-lipoprotein cholesterol that were 11 to 19 per cent below the levels in postmenopausal women who did not use hormones. The effects of estrogen-progestin balance on low-density and high-density lipoproteins may underlie the increased incidence of stroke and myocardial infarction in women of childbearing age who take oral contraceptives.

Pharmacokinetics of oral contraceptive steroids after morning or evening administration

An oral contraceptive containing ethynyloestradiol and norethisterone was administered to six women in the morning and in the evening using a cross-over design. Serum levels of ethynyloestradiol and norethisterone were measured at various times after administration. There was no significant difference in a number of pharmacokinetic parameters between the two times of administration, suggesting that morning or evening administration of the contraceptive are equally effective.

Study of plasma renin activity in Indian women using low estrogen combination pill as contraceptive [abstract]

Comgination oral contraceptives (OCs) containing ethinyl estradiol 0.05 mg and norethisterone 1 mg is known to cause various metabolic changes and hypertension is 1 of them. Both plasma renin activity (PRA) and angiotensin are considerably increased during pregnancy and these changes are attributed to estrogen induced changes in renin substrate. Recently OCs containing less amount of estrogen are in use and this study reports PRA levels in Indian women taking pills containing 0.03 mg ethinyl estradiol and 1 mg norethistrone. PRA was estimated by radioimmunoassay method in a matched control group and compared with those taking OCs for different durations. Analysis of the data revealed that the mean values for PRA in those taking the low estrogen OC pills were significantly higher than the control group of women not taking the OC.

Effects of different progestogens on lipoproteins during postmenopausal replacement therapy

To study the effects of different types of progestogens on lipoprotein metabolism, we treated three groups of postmenopausal women (six subjects each) for three weeks with estradiol valerate, 2 mg per day, and continued the treatment with different sequential estradiol-progestogen regimens as follows: Group A received norethindrone acetate, 10 mg per day, from Day 15 to Day 24 of the cycle; Group B, medroxyprogesterone acetate, 10 mg per day; and Group C, norgestrel, 0.5 mg per day. These regimens were followed by two consecutive cycles. Total cholesterol decreased in all groups by 10 to 18 per cent from the base-line values (P < 0.05). High-density-lipoprotein (HDL) cholesterol decreased by 20 per cent from the base-line level during treatment with both the estradiol-norethindrone acetate (P < 0.05) and estradiol-norgestrel (P < 0.01) regimens, whereas estradiol with medroxyprogesterone acetate was not associated with a significant change in HDL cholesterol. Our results suggest that the androgenic progestogens of the 19-nortestosterone series reverse the beneficial effect of postmenopausal estrogen treatment on HDL cholesterol, whereas the hydroxyprogesterone derivative medroxyprogesterone acetate has no such effect.

Serum levels of ethinylestradiol following its ingestion alone or in oral contraceptive formulations

The pharmacodynamics of ethinylestradiol (EE2) were studied utilizing a specific radioimmunoassay to measure serum levels in subjects ingesting EE2 alone or in combination with various gestagens. Following the administration of a single oral dose of 20 micrograms of EE2 to three postmenopausal women, peak serum levels ranging from 29 to 58 pg/ml were reached within one hour. Levels fell below the sensitivity of the assay (20 pg/ml) 2, 5 and 8 hours after ingestion. In normal menstruating women, peak serum EE2 concentrations averaged 84 +/- 27 pg/ml after the ingestion of 35 micrograms EE2 and 0.5 mg norethindrone, 152 +/- 57 pg/ml after the ingestion of 50 micrograms mestranol and 1.0 norethindrone and 201 +/- 11 pg/ml after the ingestion of 50 micrograms EE2 and 0.5 mg norgestrel. After the ingestion of mestranol, peak serum levels of EE2 were less than and occurred later than peak levels obtained after the ingestion of the same dose of EE2.