A cross-over study of three oral contraceptives containing ethinyloestradiol and either desogestrel or levonorgestrel

Effects of oral contraceptives on metabolic parameters in adult premenopausal women: a meta-analysis

OBJECTIVE

To estimate the effect of oral contraceptives (OC) containing different progestins on parameters of lipid and carbohydrate metabolism through a systematic review and meta-analysis.

PATIENTS AND METHODS

Premenopausal women aged 18 or older, who received oral contraceptives containing chlormadinone, cyproterone, drospirenone, levonorgestrel, desogestrel, dienogest, gestodene or norgestimate, for at least 3 months. Outcome variables were changes in plasma lipids, BMI, insulin resistance and plasma glucose. We searched MEDLINE and EMBASE for randomized trials and estimated the pooled within-group change in each outcome variable using a random-effects model. We performed subgroup analyses by study duration (<12 months vs ≥12 months) and polycystic ovary syndrome (PCOS) status.

RESULTS

Eighty-two clinical trials fulfilled the inclusion criteria. All progestins (except dienogest) increased plasma TG, ranging from 12.1 mg/dL for levonorgestrel (P < 0.001) to 35.1 mg/dL for chlormadinone (P < 0.001). Most progestins also increased HDLc, with the largest effect observed for chlormadinone (+9.6 mg/dL, P < 0.001) and drospirenone (+7.4 mg/dL, P < 0.001). Meanwhile, levonorgestrel decreased HDLc by 4.4 mg/dL (P < 0.001). Levonorgestrel (+6.8 mg/dL, P < 0.001) and norgestimate (+11.5 mg/dL, P = 0.003) increased LDLc, while dienogest decreased it (-7.7 mg/dL, P = 0.04). Cyproterone slightly reduced plasma glucose. None of the progestins affected BMI or HOMA-IR. Similar results were observed in subgroups defined by PCOS or study duration.

CONCLUSION

Most progestins increase both TG and HDLc, their effect on LDLc varies widely. OC have minor or no effects on BMI, HOMA-IR and glycemia. The antiandrogen progestins dienogest and cyproterone displayed the most favorable metabolic profile, while levonorgestrel displayed the least favorable.

Effects of a combined oral contraceptive containing 20 mcg of ethinylestradiol and 3 mg of drospirenone on the blood pressure, renin-angiotensin-aldosterone system, insulin resistance, and androgenic profile of healthy young women

Combined oral contraceptives (COCs) may increase the risk for cardiovascular disease depending on the ethynyl estradiol (EE) dose and the androgenicity of the progestogens. Our objective was to evaluate the impact of a COC containing 20 mcg EE + 3 mg drospirenone on blood pressure (BP), renin-angiotensin-aldosterone system, insulin resistance, and androgenic profile of healthy young women. Eighty-one healthy young women aged 30 ± 1 years (case group, n = 49, received COC; control group, n = 32, used no COC) were assessed twice, before and after the 6-month study. Statistical analysis employed the paired t-tests and expressed the data in mean and standard deviation. Results were as follows: no changes in BP or in BMI; a significant increase in aldosterone, plasma renin activity, triglycerides, and total cholesterol levels, but a non-significant increase in HDL and no significant changes in LDL levels (these parameters remained within normal ranges); a significant increase in the HOMA-IR index and a significant decrease in dehydroepiandrosterone sulfate (SDHEA), androstenedione, total testosterone, and free testosterone levels; no significant variations in the control group parameters. An oral contraceptive combination of a low EE dose and an anti-androgenic progestogen does not negatively influence the risk factors for a cardiovascular disease.

Epidemiology of hormonal contraceptives-related venous thromboembolism

For many years, it has been well documented that combined hormonal contraceptives increase the risk of venous thromboembolism (VTE). The third-generation pill use (desogestrel or gestodene (GSD)) is associated with an increased VTE risk as compared with second-generation (levonorgestrel) pill use. Other progestins such as drospirenone or cyproterone acetate combined with ethinyl-estradiol (EE) have been investigated. Most studies have reported a significant increased VTE risk among users of these combined oral contraceptives (COCs) when compared with users of second-generation pills. Non-oral combined hormonal contraception, such as the transdermal patch and the vaginal ring, is also available. Current data support that these routes of administration are more thrombogenic than second-generation pills. These results are consistent with the biological evidence of coagulation activation. Overall, the estrogenic potency of each hormonal contraceptive depending on both EE doses and progestin molecule explains the level of thrombotic risk. Some studies have shown a similar increased VTE risk among users of COCs containing norgestimate (NGM) as compared with users of second-generation pill. However, for this combination, biological data, based on quantitative assessment of sex hormone-binding globulin or haemostasis parameters, are not in agreement with these epidemiological results. Similarly, the VTE risk associated with low doses of EE and GSD is not biologically plausible. In conclusion, newer generation formulations of hormonal contraceptives as well as non-oral hormonal contraceptives seem to be more thrombogenic than second-generation hormonal contraceptives. Further studies are needed to conclude on the combinations containing NGM or low doses of EE associated with GSD.

Steroidal contraceptives: effect on carbohydrate metabolism in women without diabetes mellitus

BACKGROUND

Many hormonal contraceptives have been associated with changes in carbohydrate metabolism. Alterations may include decreased glucose tolerance and increased insulin resistance, which are risk factors for Type 2 diabetes mellitus and cardiovascular disease. These issues have been raised primarily with contraceptives containing estrogen.

OBJECTIVES

To evaluate the effect of hormonal contraceptives on carbohydrate metabolism in healthy women and those at risk for diabetes due to overweight.

SEARCH METHODS

In April 2014, we searched the computerized databases MEDLINE, POPLINE, CENTRAL, and LILACS for studies of hormonal contraceptives and carbohydrate metabolism. We also searched for clinical trials in ClinicalTrials.gov and ICTRP. The initial search also included EMBASE.

SELECTION CRITERIA

All randomized controlled trials were considered if they examined carbohydrate metabolism in women without diabetes who used hormonal contraceptives for contraception. Comparisons could be a placebo, a non-hormonal contraceptive, or another hormonal contraceptive that differed in drug, dosage, or regimen. Interventions included at least three cycles. Outcomes included glucose and insulin measures.

DATA COLLECTION AND ANALYSIS

We assessed all titles and abstracts identified during the literature searches. The data were extracted and entered into RevMan. We wrote to researchers for missing data. For continuous variables, the mean difference (MD) was computed with 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes, the Peto odds ratio with 95% CI was calculated.

MAIN RESULTS

We found 31 trials that met the inclusion criteria. No new trials were eligible in 2014. Twenty-one trials compared combined oral contraceptives (COCs); others examined different COC regimens, progestin-only pills, injectables, a vaginal ring, and implants. None included a placebo. Of 34 comparisons, eight had any notable difference between the study groups in an outcome.Twelve trials studied desogestrel-containing COCs, and the few differences from levonorgestrel COCs were inconsistent. A meta-analysis of two studies showed the desogestrel group had a higher mean fasting glucose (MD 0.20; 95% CI 0.00 to 0.41). Where data could not be combined, single studies showed lower mean fasting glucose (MD -0.40; 95% CI -0.72 to -0.08) and higher means for two-hour glucose response (MD 1.08; 95% CI 0.45 to 1.71) and insulin area under the curve (AUC) (MD 20.30; 95% CI 4.24 to 36.36).Three trials examined the etonogestrel vaginal ring and one examined an etonogestrel implant. One trial showed the ring group had lower mean AUC insulin than the levonorgestrel-COC group (MD -204.51; 95% CI -389.64 to -19.38).Of eight trials of norethisterone preparations, five compared COCs and three compared injectables. In a COC trial, a norethisterone group had smaller mean change in glucose two-hour response than a levonorgestrel-COC group (MD -0.30; 95% CI -0.54 to -0.06). In an injectable study, a group using depot medroxyprogesterone acetate had higher means than the group using norethisterone enanthate for fasting glucose (MD 10.05; 95% CI 3.16 to 16.94), glucose two-hour response (MD 17.00; 95% CI 5.67 to 28.33), and fasting insulin (MD 3.40; 95% CI 2.07 to 4.73).Among five recent trials, two examined newer COCs with different estrogen types. One showed the group with nomegestrel acetate plus 17β-estradiol had lower means than the levonorgestrel group for incremental AUC glucose (MD -1.43; 95% CI -2.55 to -0.31) and glycosylated hemoglobin (HbA1c) (MD -0.10; 95% CI -0.18 to -0.02). Two trials compared extended versus conventional (cyclic) regimens. With a dienogest COC, an extended-use group had greater mean change in AUC glucose (MD 82.00; 95% CI 10.72 to 153.28). In a small trial using two levonorgestrel COCs, the lower-dose group showed smaller mean change in fasting glucose (MD -3.00; 95% CI -5.89 to -0.11), but the obese and normal weight women did not differ significantly.

AUTHORS' CONCLUSIONS

Current evidence suggests no major differences in carbohydrate metabolism between different hormonal contraceptives in women without diabetes. We cannot make strong statements due to having few studies that compared the same types of contraceptives. Many trials had small numbers of participants and some had large losses. Many of the earlier studies had limited reporting of methods.We still know very little about women at risk for metabolic problems due to being overweight. More than half of the trials had weight restrictions as inclusion criteria. Only one small trial stratified the groups by body mass index (obese versus normal).

The effect of combined oral contraception on testosterone levels in healthy women: a systematic review and meta-analysis

BACKGROUND; Combined oral contraceptives (COCs) reduce levels of androgen, especially testosterone (T), by inhibiting ovarian and adrenal androgen synthesis and by increasing levels of sex hormone-binding globulin (SHBG). Although this suppressive effect has been investigated by numerous studies over many years, to our knowledge no systematic review concerning this issue had been performed. This systematic review and meta-analysis was performed to evaluate the effect of COCs on concentrations of total T, free T and SHBG in healthy women and to evaluate differences between the various types of COCs (e.g. estrogen dose, type of progestin) and the assays used to assess total T and free T.

METHODS

A review of the literature was performed using database searches (MEDLINE, EMBASE and the Cochrane Central Register of Clinical Trials) and all publications (from inception date until July 2012) investigating the effect of COCs on androgen levels in healthy women were considered eligible for selection. Three reviewers were involved in study selection, data extraction and critical appraisal. For the meta-analysis, data on total T, free T and SHBG were extracted and combined using random effects analysis. Additional subgroup analyses were performed to evaluate differences between the various types of COCs (e.g. estrogen dose, type of progestin) and the assays used to assess total T or free T.

RESULTS

A total of 151 records were identified by systematic review and 42 studies with a total of 1495 healthy young women (age range: 18-40 years) were included in the meta-analysis. All included studies were experimental studies and 21 were non-comparative. Pooling of the results derived from all the included papers showed that total T levels significantly decreased during COC use [mean difference (MD) (95% confidence interval, CI) -0.49 nmol/l (-0.55, -0.42); P < 0.001]. Significantly lower levels of free T were also found [relative change (95% CI) 0.39 (0.35, 0.43); P < 0.001], with a mean decrease of 61%. On the contrary, SHBG concentrations significantly increased during all types of COC use [MD (95% CI) 99.08 nmol/l (86.43, 111.73); P < 0.001]. Subgroup analyses revealed that COCs containing 20-25 µg EE had similar effects on total and free T compared with COCs with 30-35 µg EE. In addition, suppressive effects on T levels were not different when comparing different types of progestins. However, subgroup analyses for the estrogen dose and the progestin type in relation to changes in SHBG levels did show significant differences: COCs containing second generation progestins and/or the lower estrogen doses (20-25 µg EE) were found to have less impact on SHBG concentrations.

CONCLUSIONS

The current literature review and meta-analysis demonstrates that COCs decrease circulating levels of total T and free T and increase SBHG concentrations. Due to the SHBG increase, free T levels decrease twice as much as total T. The estrogen dose and progestin type of the COC do not influence the decline of total and free T, but both affect SHBG. The clinical implications of suppressed androgen levels during COC use remain to be elucidated.

Sex hormone-binding globulin levels are not causally related to venous thrombosis risk in women not using hormonal contraceptives

BACKGROUND

Oral contraceptive use increases the risk of venous thrombosis as well as sex hormone-binding globulin (SHBG) levels. Furthermore, increased SHBG levels are positively associated with activated protein C (APC) resistance and thrombotic risk in oral contraceptive users.

OBJECTIVES

To determine whether increased SHBG levels are causally related to venous thrombosis in women not using hormonal contraceptives.

METHODS

Premenopausal women were selected from a case-control study on venous thrombosis, the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA) study (23 patients; 258 controls). Women using hormonal contraceptives were excluded. First, the risk of venous thrombosis with SHBG levels above the normal reference range (70 nm) was determined. Second, because multiple regulatory factors affect SHBG levels and residual confounding may remain, we determined six single-nucleotide polymorphisms (SNPs) in the SHBG gene and assessed the risk of venous thrombosis in a different case-control study, the Leiden Thrombophilia Study (LETS) (20 patients; 74 controls), and in the MEGA study. Finally, the association between SHBG levels and the normalized activated partial thromboplastin time-based APC resistance (an intermediate endpoint for venous thrombosis) was determined.

RESULTS

Elevated SHBG levels (> 70.0 nm) were associated with venous thrombosis (odds ratio 1.92; 95% confidence interval [CI] 0.74-5.00). However, this finding can be explained by residual confounding. Two SNPs in the SHBG gene affected SHBG levels, but not venous thrombosis risk. Furthermore, SHBG levels in controls were not associated with APC resistance (SHBG level, > 70.0 vs. ≤ 70.0 nm: mean difference in normalized APC sensitivity ratio, 0.03; 95% CI -0.05 to 0.10). Exclusion of women with FV Leiden did not materially change these results.

CONCLUSIONS

Increased SHBG levels are not causally related to the risk of venous thrombosis.

Using changes in binding globulins to assess oral contraceptive compliance

BACKGROUND

Validity of oral contraceptive pill (OCP) clinical trial results depends on participant compliance. Ethinyl estradiol (EE2) induces increases in hepatic binding globulin (BG) levels. Measuring these BG increases may provide an effective and convenient approach to distinguish noncompliant from compliant OCP users in research settings. This analysis evaluated the usefulness of measuring increases in corticosteroid-, sex-hormone- and thyroxine-binding globulins (CBG, SHBG and TBG, respectively) as measures of OCP compliance.

METHODS

We used frozen serum from a trial that compared ovarian suppression between normal-weight and obese women randomized to one of two OCPs containing EE2 and levonorgestrel (LNG). Based on serial LNG measurements during the trial, 17% of participants were noncompliant. We matched noncompliant participants with compliant participants by age, body mass index, ethnicity and OCP formulation. We measured CBG, SHBG and TBG levels and compared change from baseline to 3-month follow-up between the noncompliant and compliant participants. Construction of receiver operator characteristic (ROC) curves allowed comparison of various BG measures.

RESULTS

Changes in CBG and TBG distinguished OCP noncompliant users from compliant users [area under the ROC curve (AUROC), 0.86 and 0.89, p<.01]. Changes in SHBG were less discriminating (AUROC 0.69)

CONCLUSIONS

EE2-induced increases in CBG and TBG provide a sensitive integrated marker of compliance with an LNG-containing OCP.

Steroidal contraceptives: effect on carbohydrate metabolism in women without diabetes mellitus

BACKGROUND

Many hormonal contraceptives have been associated with changes in carbohydrate metabolism. Alterations may include decreased glucose tolerance and increased insulin resistance, which are risk factors for Type 2 diabetes mellitus and cardiovascular disease. These issues have been raised primarily with contraceptives containing estrogen.

OBJECTIVES

To evaluate the effect of hormonal contraceptives on carbohydrate metabolism in healthy women and those at risk for diabetes due to overweight.

SEARCH METHODS

In February 2012, we searched the computerized databases MEDLINE, POPLINE, CENTRAL, and LILACS for studies of hormonal contraceptives and carbohydrate metabolism. We also searched for clinical trials in ClinicalTrials.gov and ICTRP. Previous searches also included EMBASE.

SELECTION CRITERIA

All randomized controlled trials were considered if they examined carbohydrate metabolism in women without diabetes who used hormonal contraceptives for contraception. Comparisons could be a placebo, a non-hormonal contraceptive, or another hormonal contraceptive that differed in drug, dosage, or regimen. Interventions included at least three cycles. Outcomes included glucose and insulin measures.

DATA COLLECTION AND ANALYSIS

We assessed all titles and abstracts identified during the literature searches. The data were extracted and entered into RevMan. We wrote to researchers for missing data. For continuous variables, the mean difference (MD) was computed with 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes, the Peto odds ratio with 95% CI was calculated.

MAIN RESULTS

We found 31 trials that met the inclusion criteria. Twenty-one trials compared combined oral contraceptives (COCs); others examined different COC regimens, progestin-only pills, injectables, a vaginal ring, and implants. None included a placebo. Of 34 comparisons, eight had any notable difference between the study groups in an outcome.Twelve trials studied desogestrel-containing COCs, and the few differences from levonorgestrel COCs were inconsistent. A meta-analysis of two studies showed the desogestrel group had a higher mean fasting glucose (MD 0.20; 95% CI 0.00 to 0.41). Where data could not be combined, single studies showed lower mean fasting glucose (MD -0.40; 95% CI -0.72 to -0.08) and higher means for two-hour glucose response (MD 1.08; 95% CI 0.45 to 1.71) and insulin area under the curve (AUC) (MD 20.30; 95% CI 4.24 to 36.36).Three trials examined the etonogestrel vaginal ring and one examined an etonogestrel implant. One trial showed the ring group had lower mean AUC insulin than the levonorgestrel-COC group (MD -204.51; 95% CI -389.64 to -19.38).Of eight trials of norethisterone preparations, five compared COCs and three compared injectables. In a COC trial, a norethisterone group had smaller mean change in glucose two-hour response than a levonorgestrel-COC group (MD -0.30; 95% CI -0.54 to -0.06). In an injectable study, a group using depot medroxyprogesterone acetate had higher means than the group using norethisterone enanthate for fasting glucose (MD 10.05; 95% CI 3.16 to 16.94), glucose two-hour response (MD 17.00; 95% CI 5.67 to 28.33), and fasting insulin (MD 3.40; 95% CI 2.07 to 4.73).Among five recent trials, two examined newer COCs with different estrogen types. One showed the group with nomegestrel acetate plus 17β-estradiol had lower means than the levonorgestrel group for incremental AUC glucose (MD -1.43; 95% CI -2.55 to -0.31) and glycosylated hemoglobin (HbA1c) (MD -0.10; 95% CI -0.18 to -0.02). Two trials compared extended versus conventional (cyclic) regimens. With a dienogest COC, an extended-use group had greater mean change in AUC glucose (MD 82.00; 95% CI 10.72 to 153.28). In a small trial using two levonorgestrel COCs, the lower-dose group showed smaller mean change in fasting glucose (MD -3.00; 95% CI -5.89 to -0.11), but the obese and normal weight women did not differ significantly.

AUTHORS' CONCLUSIONS

Current evidence suggests no major differences in carbohydrate metabolism between different hormonal contraceptives in women without diabetes. We cannot make strong statements due to having few studies that compared the same types of contraceptives. Many trials had small numbers of participants and some had large losses. Many of the earlier studies had limited reporting of methods.We still know very little about women at risk for metabolic problems due to being overweight. More than half of the trials had weight restrictions as inclusion criteria. Only one small trial stratified the groups by body mass index (obese versus normal).

Safety and efficacy of contraception--Why should the obese woman be any different?

The public health impact of obesity and unintended pregnancy is profound with far reaching consequences. Obese women are less likely to use contraception due to a variety of self-induced and systems-based barriers but their risk of becoming pregnant is similar to their normal weight counterparts. However, pregnancy-associated risks for obese women are higher than that of normal weight women and thus, pregnancy generally outweighs the risks of contraceptive use. Adequate counselling to prevent and/or plan for pregnancy is imperative for these women. Research that investigates the relationship between obesity and contraceptive use is urgently needed.

Metabolic effects of contraceptive steroids

Estrogen and progestins have been used by millions of women as effective combined contraceptives. The safety of hormonal contraceptives has been documented by years of follow-up and serious adverse events that may be related to their use are rare in the young population exposed to these agents. The balance between the benefits and the risks of contraceptive steroids is generally positive in particular when comparing to the risks of pregnancy and especially in women with risk factors. The metabolic changes induced by the synthetic steroids used in contraception, such as lipoprotein changes, insulin response to glucose, and coagulation factors have been considered as potential markers of cardiovascular and venous risk. Observations of these effects have led to modifications of the composition of hormonal contraceptive in order to minimize these changes and hence potentially decrease the risks. The synthetic estrogen Ethinyl-Estradiol (EE) exerts a stronger effect that natural estradiol (E2) on hepatic metabolism including estrogen-dependent markers such as liver proteins. This stronger hepatic impact of EE has been related to its 17α-ethinyl group which prevents the inactivation of the molecule and results in a more pronounced hepatic effect of EE as compared to estradiol. Due to its strong activity, administering EE via a non-oral route does not prevent its impact on liver proteins. In order to circumvent the metabolic changes induced by EE, newer products using more natural compounds such as estradiol (E2) and estradiol valerate (E2V) have been introduced. The synthetic progestins used for contraception are structurally related either to testosterone (T) (estranes and gonanes) or to progesterone (pregnanes and 19-norpregnanes). Several new progestins have been designed to bind more specifically to the progesterone receptor and to minimize side-effects related to androgenic, estrogenic or glucocorticoid receptor interactions. Dienogest (DNG), and drospirenone (DRSP) and the 19-norpregnanes including Nestorone® (NES), nomegestrol acetate (NOMAc) and trimegestone (TMG) have been combined with estrogen either EE or E2 or estradiol valerate (E2V). Risks and benefits of the newer progestins used in contraception depend upon the type of molecular structure, the type and dose of estrogen associated in a combination and the route of administration. The lower metabolic impact of estradiol-based combinations may result in an improved safety profile, but large surveillance studies are warranted to confirm this plausible hypothesis. So far, the contraindications and warnings for use of current COCs also apply to the estradiol-based COCs.

Effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on lipid metabolism during 1 year of conventional or extended-cycle use

BACKGROUND

The effects of extended regimens of combined oral contraceptives (COC) on lipid parameters are largely unknown. The present study compared the effects of a COC containing 30 mcg ethinyl estradiol and 2 mg dienogest (EE/DNG) in conventional and extended-cycle regimen over 1 year.

STUDY DESIGN

Lipid parameters were measured in 59 women treated with EE/DNG either conventionally (21+7 days) or in extended-cycle regimen (84+7 days). Blood samples were taken in a control cycle and at 3 and 12 months of treatment.

RESULTS

The mean levels of total cholesterol, HDL cholesterol and HDL(2) cholesterol underwent modest to moderate significant increases over time, while the significant increase in triglycerides and VLDL cholesterol was more pronounced with both regimens. LDL cholesterol decreased slightly in both regimen groups, whereas lipoprotein(a) was transiently decreased at 3 months only in the extended-cycle group. The changes reached a steady-state at latest at 3 months, but did not exceed the given normal ranges for any of the parameters. Notably, except for lipoprotein(a), the changes in mean lipid levels were not significantly different in the conventional and the extended-cycle regimen at 3 or 12 months of treatment.

CONCLUSION

Use of EE/DNG in conventional or extended-cycle regimen resulted in comparable changes of lipid parameters.

Steroidal contraceptives: effect on carbohydrate metabolism in women without diabetes mellitus

BACKGROUND

Many hormonal contraceptives have been associated with changes in carbohydrate metabolism. Alterations may include decreased glucose tolerance and increased insulin resistance, which are risk factors for Type 2 diabetes mellitus and cardiovascular disease. These issues have been raised with progestin-only contraceptives as well as contraceptives containing estrogen. Such potential effects could influence recommendations for, and use of, these widely used and effective contraceptives.

OBJECTIVES

To evaluate the effect of hormonal contraceptives on carbohydrate metabolism in healthy women and those at risk for diabetes due to overweight.

SEARCH STRATEGY

We searched the computerized databases MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS for studies of hormonal contraceptives and carbohydrate metabolism. We also searched for clinical trials in ClinicalTrials.gov and ICTRP. We wrote to investigators for information about other published or unpublished trials.

SELECTION CRITERIA

All randomized controlled trials were considered if they examined carbohydrate metabolism in women without diabetes who used hormonal contraceptives for contraception. Interventions could include comparisons of a hormonal contraceptive with a placebo, a non-hormonal contraceptive, or another hormonal contraceptive that differed in drug, dosage, or regimen. Interventions included at least three cycles. Outcomes included glucose and insulin levels, which were generally reported as fasting value or response to an oral glucose tolerance test.

DATA COLLECTION AND ANALYSIS

We assessed for inclusion all titles and abstracts identified during the literature searches with no language limitations. The data were abstracted and entered into RevMan. Studies were examined for methodological quality. For continuous variables, the mean difference was computed with 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes, the Peto odds ratio with 95% CI was calculated.

MAIN RESULTS

We found 43 trials that met the inclusion criteria. No study stratified by body weight (normal-weight versus overweight women). Results for desogestrel were often favorable regarding carbohydrate metabolism but inconsistent overall. Glucose and insulin means were more favorable for norethisterone in studies of progestin-only contraceptives. For other progestins, little or no difference was noted across trials.

AUTHORS' CONCLUSIONS

Current evidence suggests that hormonal contraceptives have limited effect on carbohydrate metabolism in women without diabetes. Strong statements cannot be made, though, due to having few studies that compared any particular types of contraceptives. Many trials had small numbers of participants and some had large losses. Many studies had poor reporting of methods. No information was available regarding the effects among women who were overweight.

A comparative study on the effects of a contraceptive vaginal ring NuvaRing®and an oral contraceptive on carbohydrate metabolism and adrenal and thyroid function

OBJECTIVES

To compare carbohydrate metabolism, adrenal and thyroid function during use of a combined contraceptive vaginal ring (NuvaRing, NV Organon, Oss, The Netherlands) with those of a combined oral contraceptive.

METHODS

Healthy women aged 18-40 years used either the vaginal ring, delivering 15 microg ethinylestradiol and 120 microg of etonogestrel per day, or a combined oral contraceptive containing 30 microg ethinylestradiol and 150 microg levonorgestrel, for six cycles. Each cycle comprised 3 weeks of use of the ring or the pill followed by 1 ring- or pill-free week. The following parameters were measured at baseline and at the end of cycles 3 and 6: carbohydrate metabolism (glucose, insulin, glycosylated hemoglobin); adrenal function (total cortisol, cortisol binding globulin, dehydroepiandrosterone sulfate); thyroid function (thyroid stimulating hormone, free thyroxine).

RESULTS

Small and similar increases in insulin were seen in both groups. Concentrations of cortisol binding globulin and total cortisol rose significantly less during ring use than during combined oral contraceptive use (cycle 3, p= 0.0002; cycle 6, p < 0.0001). Levels of dehydroepiandrosterone sulfate did not change in either group. Thyroid stimulating hormone levels increased significantly more in the ring group at cycle 3 (p = 0.0016) but free thyroxine levels were unchanged in both groups.

CONCLUSIONS

Both the vaginal ring and the oral contraceptive have no clinically relevant effects on carbohydrate metabolism, adrenal or thyroid function.

Insulin sensitivity and lipid metabolism with oral contraceptives containing chlormadinone acetate or desogestrel: a randomized trial

BACKGROUND

Second-generation and third-generation oral contraceptives containing 30 mcg or more of ethinylestradiol (EE) decrease insulin sensitivity (SI). In this study, we investigated whether SI is decreased by contraceptives containing lower doses EE or by progestins with antiandrogenic properties.

STUDY DESIGN

Twenty-eight young healthy women were randomly allocated to receive 20 mcg of EE and 150 mcg of desogestrel (DSG) (n=14) or 30 mcg of EE and 2 mg of chlormadinone acetate (CMA) (n=14) for 6 months. SI and glucose utilization independent of insulin (Sg) were investigated by the minimal model method. Lipid modifications were also analyzed.

RESULTS

SI decreased with EE/DSG (7.09+/-1.4 vs. 4.30+/-0.91; p=.04; n=12), but not with EE/CMA (5.79+/-0.93 vs. 6.79+/-1.1; p=.48; n=12). SI modifications observed in the two groups were significantly different (-2.79+/-1.15 vs. 1.0+/-1.38; p=.05). Sg did not vary with either treatment. The response of C-peptide to glucose increased, but significantly so only with EE/CMA (p=.01). The C-peptide/insulin response increased with both EE/DSG (p=.05) and EE/CMA (p=.04). High-density lipoprotein (HDL) cholesterol (p=.02) and triglycerides (p=.02 and p=.01) increased in both groups, but HDL/low-density lipoprotein cholesterol (p=.02), apoprotein A1 (Apo-A1) (p=.04) and Apo-A1/apoprotein B (p=.048) increased significantly only with EE/CMA.

CONCLUSIONS

The present study confirms that DSG, even when associated with low EE dose, decreases SI. By contrast, EE/CMA does not deteriorate SI and induces a favorable lipid profile.

20 microg versus >20 microg estrogen combined oral contraceptives for contraception

BACKGROUND

Concern about estrogen-related adverse effects has led to progressive reductions in the estrogen dose in combination oral contraceptives (COCs). However, reducing the amount of estrogen to improve safety could result in decreased contraceptive effectiveness and unacceptable changes in bleeding patterns.

OBJECTIVES

To test the hypothesis that COCs containing </=20 microg ethinyl estradiol (EE) perform similarly as those containing >20 microg in terms of contraceptive effectiveness, bleeding patterns, discontinuation, and side effects.

SEARCH STRATEGY

We searched computerized databases (CENTRAL, MEDLINE, EMBASE, and POPLINE) up to January 2008, and searched the references of eligible trials. We wrote to oral contraceptive manufacturers to identify eligible trials.

SELECTION CRITERIA

English-language reports of randomized controlled trials were eligible that compare a COC containing </=20 microg EE with a COC containing >20 microg EE. We excluded studies where the interventions were designed to be administered for less than three consecutive cycles or to be used primarily as treatment for non-contraceptive conditions. Trials had to report on contraceptive effectiveness, bleeding patterns, trial discontinuation due to bleeding-related reasons or other side effects, or side effects to be included in the review.

DATA COLLECTION AND ANALYSIS

The primary reviewer evaluated all titles and abstracts located in the literature searches to determine whether they met the inclusion criteria. Two reviewers independently extracted data from the studies identified for inclusion. We wrote to the authors when clarifications or additional data were needed. Data were entered and analyzed with RevMan 4.2.

MAIN RESULTS

No differences were found in contraceptive effectiveness for the 13 COC pairs for which this outcome was reported. Compared to the higher-estrogen pills, several COCs containing 20 microg EE resulted in higher rates of early trial discontinuation (overall and due to adverse events such as irregular bleeding) as well as increased risk of bleeding disturbances (both amenorrhea or infrequent bleeding and irregular, prolonged, frequent bleeding, or breakthrough bleeding or spotting).

AUTHORS' CONCLUSIONS

While COCs containing 20 microg EE may be theoretically safer, this review did not focus on the rare events required to assess this hypothesis. Data from existing randomized controlled trials are inadequate to detect possible differences in contraceptive effectiveness. Low-dose estrogen COCs resulted in higher rates of bleeding pattern disruptions. However, most trials compared COCs containing different progestin types, and changes in bleeding patterns could be related to progestin type as well as estrogen dose. Higher follow-up rates are essential for meaningful interpretation of results.

Steroidal contraceptives: effect on carbohydrate metabolism in women without diabetes mellitus

BACKGROUND

Many hormonal contraceptives have been associated with changes in carbohydrate metabolism. Alterations may include decreased glucose tolerance and increased insulin resistance, which are risk factors for Type 2 diabetes mellitus and cardiovascular disease. These issues have been raised with progestin-only contraceptives as well as contraceptives containing estrogen. Such potential effects could influence recommendations for, and use of, these widely used and effective contraceptives.

OBJECTIVES

To evaluate the effect of hormonal contraceptives on carbohydrate metabolism in healthy women and those at risk for diabetes due to overweight.

SEARCH STRATEGY

We searched the computerized databases MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS for studies of hormonal contraceptives and carbohydrate metabolism. The latest search was conducted in March 2006. We wrote to investigators for information about other published or unpublished trials.

SELECTION CRITERIA

All randomized controlled trials (RCTs) were considered if they examined carbohydrate metabolism in women without diabetes who used hormonal contraceptives for contraception. Interventions included comparisons of a hormonal contraceptive with a placebo, a non-hormonal contraceptive, or another hormonal contraceptive that differed in drug, dosage, or regimen. Interventions included at least three cycles. Outcomes included glucose and insulin levels, which were generally reported as fasting value or response to an oral glucose tolerance test.

DATA COLLECTION AND ANALYSIS

We assessed for inclusion all titles and abstracts identified during the literature searches with no language limitations. The data were abstracted and the information was entered into RevMan. Studies were examined for methodological quality. For continuous variables, the weighted mean difference was computed with 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes, the Peto odds ratio (OR) with 95% CI was calculated.

MAIN RESULTS

A total of 39 trials met the inclusion criteria. No study stratified by body weight (normal-weight versus overweight women). Results for desogestrel were often favorable regarding carbohydrate metabolism but inconsistent overall. Glucose and insulin means were more favorable for norethisterone in studies of progestin-only contraceptives. For other progestins, little or no difference was noted across trials.

AUTHORS' CONCLUSIONS

Current evidence suggests that hormonal contraceptives have limited effect on carbohydrate metabolism in women without diabetes. Strong statements cannot be made, though, due to having few studies that compared any particular types of contraceptives. Many trials had small numbers of participants and some had large losses to follow up. Most studies had poor reporting of methods. No information was available regarding the effects among women who were overweight.

Effects of two combined oral contraceptives containing ethinyl estradiol 20 μg combined with either drospirenone or desogestrel on lipids, hemostatic parameters and carbohydrate metabolism

OBJECTIVE

To compare the effect of ethinyl estradiol 20 microg/drospirenone 3 mg (EE 20 microg/DRSP 3 mg) administered according to a 24/4 regimen with ethinyl estradiol 20 microg/desogestrel 150 microg (EE 20 microg/DSG 150 microg) administered according to the conventional 21/7 regimen on lipid, carbohydrate and hemostatic parameters.

STUDY DESIGN

In this open-label study, healthy women were randomized to EE 20 microg/DRSP 3 mg or EE 20 microg/DSG 150 microg for seven cycles. Mean differences in high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol levels at cycle 7 compared to baseline were assessed. Secondary variables included changes in other lipid, hemostatic and carbohydrate parameters.

RESULTS

Both treatments increased HDL-cholesterol, but decreased LDL-cholesterol by a comparable extent. Although slightly elevated in both groups, blood glucose and C-peptide levels measured during oral glucose tolerance tests were within normal reference ranges at cycle 7. Overall, the differences in lipid, hemostatic or carbohydrate parameters were not significant between the two treatments.

CONCLUSION

EE 20 microg/DRSP 3 mg has a good safety profile comparable with EE 20 microg/DSG 150 microg.

20 mcg versus >20 mcg estrogen combined oral contraceptives for contraception

BACKGROUND

Concern about estrogen-related adverse effects has led to progressive reductions in the estrogen dose in combination oral contraceptives (COCs). However, reducing the amount of estrogen to improve safety also could result in decreased contraceptive effectiveness and unacceptable changes in bleeding patterns.

OBJECTIVES

To test the hypothesis that COCs containing </=20 mcg ethinyl estradiol (EE) perform similarly as those containing >20 mcg in terms of contraceptive effectiveness, bleeding patterns, discontinuation, and side effects.

SEARCH STRATEGY

We searched computerized databases (CENTRAL, MEDLINE, EMBASE, and POPLINE) from their inception to November 2003, searched the references of eligible trials, and wrote to oral contraceptive manufacturers to identify eligible trials.

SELECTION CRITERIA

English-language reports of randomized controlled trials that compare a COC containing </=20 mcg EE with a COC containing >20 mcg EE were eligible. We excluded studies where the interventions were designed to be administered for less than three consecutive cycles or to be used primarily as treatment for non-contraceptive conditions. Trials had to report on contraceptive effectiveness, bleeding patterns, trial discontinuation due to bleeding-related reasons or other side effects, or side effects to be included in the review.

DATA COLLECTION AND ANALYSIS

The primary reviewer evaluated all titles and abstracts located in the literature searches to determine whether they met the inclusion criteria. Two reviewers independently extracted data from the studies identified for inclusion. We wrote to the authors when clarifications or additional data were needed. Data were entered and analyzed with RevMan 4.2.

MAIN RESULTS

No differences were found in contraceptive effectiveness for the 11 COC pairs for which this outcome was reported. Several COCs containing 20 mcg EE resulted in higher rates of early trial discontinuation (overall and due to adverse events such as irregular bleeding) as well as increased risk of bleeding disturbances (both amenorrhea/infrequent bleeding and irregular, prolonged, frequent bleeding, or breakthrough bleeding or spotting) than their higher-estrogen comparison pills.

AUTHORS' CONCLUSIONS

While COCs containing 20 mcg EE may be theoretically safer, this review did not focus on the rare events required to assess this hypothesis. Data from randomized controlled trials are inadequate to detect possible differences in contraceptive effectiveness. Low-dose estrogen COCs resulted in higher rates of bleeding pattern disruptions. However, most trials compared COCs containing different progestin types, and changes in bleeding patterns could be related to progestin type as well as estrogen dose.

Serum ceruloplasmin and ferroxidase activity are not decreased in hepatic failure related to alcoholic cirrhosis: clinical and pathophysiological implications

BACKGROUND

A decrease in serum ceruloplasmin (Cp), a protein involved in iron metabolism through its ferroxidase activity, is classically claimed to be observed in severe hepatic failure of non-wilsonian chronic liver disease and therefore to be a confounding factor for the diagnosis of Wilson's disease. Moreover, a simultaneous decrease in ferroxidase activity could be hypothesized as playing a role in the development of the hepatic siderosis frequently observed in advanced chronic liver diseases. The aim of this study was to test the validity of these two statements.

METHODS

This study investigated Cp, determined by immunonephelometry, and its ferroxidase 1 activity determined by Erel's method in 33 male patients with severe alcoholic cirrhosis compared with 66 healthy male volunteers, selected on strict criteria. Each patient was age-matched with two controls. Nonparametric tests were used for statistical analysis.

RESULTS

The mean values of Cp were significantly higher in cirrhotic patients as compared with control subjects. A significant elevation of Cp was also observed in the subgroup of 11 cirrhotic patients who had normal serum C-reactive protein levels. The mean values of ferroxidase 1 activity were similar to those obtained in control subjects.

CONCLUSIONS

Low serum Cp should not be expected in severe hepatic cirrhosis of non-wilsonian origin. Hepatic siderosis in advanced chronic liver disease is likely to be unrelated to decreased ferroxidase activity.

FFPRHC Guidance (October 2003): First Prescription of Combined Oral Contraception

The Guidance provides information for clinicians on the steps to be taken before providing a woman with her first prescription for combined oral contraception. It updates and replaces previous Faculty Guidance. A key to the grades of recommendations, based on levels of evidence, is given at the end of this document. Details of the methods used by the Clinical Effectiveness Unit (CEU) in developing this Guidance, and evidence tables summarising the research basis of the recommendations, are available on the Faculty website (www.ffprhc.org.uk). Abbreviations used include: blood pressure (BP), body mass (BMI), bone mineral density (BMD), breakthrough bleeding (BTB), British National Formulary (BNF), combined oral contraception (COC), Committee on Safety of Medicines (CSM), confidence interval (CI), deep vein thrombosis (DVT), emergency contraception (EC), ethinyl oestradiol (EE), Faculty Aid to Continuing Professional Development Topics (FACT), Family Planning Association (fpa), follicule-stimulating homone (FSH), general practitioner (GP), intermenstrual bleeding (IMB), luteinising hormone (LT), microgram, myocardial infarction (MI), odds ratio (OR), oral contraception (OC), pulmonary embolism (PE), relative risk (RR), Scottish Intercollegiate Guideline Network (SIGN), sexually transmitted infection (STI), Summary of Product Characteristics (SPCs), venous thomboembolism (VTE), World Health Organization (WHO), WHO Medical Eligibility Criteria (WHOMEC), WHO Selected Practice Recommendations (WHOSPR).

A randomized study over 13 cycles to assess the influence of oral contraceptives containing ethinylestradiol combined with drospirenone or desogestrel on carbohydrate metabolism

In this open-label, randomized study we compared the influence of a new oral contraceptive containing 30 microg ethinylestradiol and 3 mg drospirenone (Yasmin) with a reference preparation containing 30 microg ethinylestradiol and 150 microg desogestrel (Marvelon) on variables of carbohydrate metabolism by means of oral glucose tolerance tests at baseline and in the 6th and 13th treatment cycle. The mean levels of fasting glucose and insulin were similar at baseline and after 13 treatment cycles, whereas C-peptide and free fatty acid levels decreased slightly in both groups. All blood glucose and insulin values measured in the oral glucose tolerance tests were within normal ranges, despite a slight increase in the mean areas under the curves of 0-3 h [AUCs (0-3 h)] of both variables from baseline to treatment cycle 13. Differences between both treatments were not statistically significant. The mean AUCs (0-3 h) for C-peptide were not markedly changed in any treatment group. Free fatty acid levels decreased by 42% in the drospirenone group and increased by 48.9% in the desogestrel group, in terms of means of individual changes. Both preparations were well tolerated and equally efficacious regarding contraception and cycle control. The mean body weight was slightly decreased in most cycles during treatment with the drospirenone combination, as compared to baseline, while it was slightly increased versus baseline in all cycles during treatment with the desogestrel combination. The combination with drospirenone had less impact on blood pressure than the combination with desogestrel. In conclusion, Yasmin, a combined low-dose oral contraceptive with 30 microg ethinylestradiol and 3 mg of the novel progestogen drospirenone, as well as the reference Marvelon, containing 30 microg ethinylestradiol and 150 microg desogestrel had little impact on carbohydrate metabolism when used for 1 year. The observed changes were small and not suggestive of a clinically relevant deterioration of carbohydrate metabolism.

Serum ceruloplasmin and ferroxidase activity are decreased in HFE C282Y homozygote male iron-overloaded patients

BACKGROUND/AIMS

A body of evidence suggests that ceruloplasmin (Cp), the major serum copper-containing protein, acts in iron metabolism due to its ferroxidase activity which appears essential for iron movements and exchanges.

METHODS

The present study investigated the serum levels of Cp and its ferroxidase activity in 53 C282Y homozygote genetic hemochromatosis (38 iron overloaded, 15 iron depleted) patients as compared to age and sex-matched healthy volunteers.

RESULTS

Serum levels of Cp were significantly decreased in iron-overloaded male hemochromatotic patients vs. the control group (P=0.02). Furthermore, serum ferroxidase activity was strongly and significantly lower in iron-overloaded male hemochromatotic patients (P<0.001). In contrast, in iron-depleted male hemochromatotic patients, who were under maintenance therapy by regular phlebotomies, serum levels of Cp and ferroxidase activity were not statistically different from those observed in controls.

CONCLUSIONS

These data: (i) show that serum Cp and ferroxidase activity are decreased when C282Y homozygote men are iron overloaded and normal when iron depleted; (ii) suggest that iron may modulate the Cp gene expression; and (iii) raise the issue of the putative role of decreased serum ferroxidase activity in the phenotypic expression of HFE-1 hereditary hemochromatosis.

Minimal androgenic activity of a new oral contraceptive containing norethindrone acetate and graduated doses of ethinyl estradiol

The pharmacokinetics and androgenic activity of Estrostep, a new oral contraceptive providing low-dose estrogen in a graduated sequence with a constant dose of progestin, were characterized in an open-label, nonrandomized study in 17 normally cycling women treated for three cycles with Estrostep. Women received 1 mg of norethindrone acetate daily combined with 20 microg of ethinyl estradiol daily for the first 5 days (1/20), 30 microg of ethinyl estradiol daily for the next 7 days (1/30), and 35 microg of ethinyl estradiol daily for 9 days (1/35). No medication was given for 7 days in each cycle to allow for withdrawal bleeding. Serial blood samples for the measurement of ethinyl estradiol and norethindrone concentrations were collected on days 5, 12, and 21 of the third treatment cycle for the 1/20, 1/30, and 1/35 dose, respectively. Sex hormone-binding globulin (SHBG) and free testosterone were measured at baseline, on day 1 of cycles 2 and 3 (SHBG only), and on days 5, 12, and 21 of cycle 3. Mean steady-state plasma ethinyl estradiol and norethindrone concentrations increased over cycle 3. The increases in ethinyl estradiol concentrations were proportional to dose. The increases in norethindrone concentrations were related to ethinyl estradiol-dependent increases in SHBG concentrations, which were 218%, 253%, and 296% of baseline values on days 5, 12, and 21, respectively. Mean plasma free testosterone concentrations decreased 47%, 60%, and 64% below baseline on days 5, 12, and 21 of cycle 3, respectively. Graduated ethinyl estradiol doses combined with a constant norethindrone acetate dose progressively increase SHBG and decrease free testosterone, which overrides any theoretic concerns of androgenic activity of norethindrone acetate. Although true androgenic activity can be determined only by assessing endpoints such as acne, hirsutism, and lipids in large controlled trials, the observed changes in circulating SHBG and free testosterone concentrations indicate that Estrostep has little, if any, intrinsic androgenic activity.

The androgenicity of progestins

All steroid hormones are structurally similar, but relatively minor differences cause profound alterations in biochemical activity. The 21-carbon series (pregnane nucleus) includes the corticoids and the true progestins (e.g., medroxyprogesterone acetate). The 19-carbon series (androstane nucleus) includes all the androgens, among them the progestins used in most oral and parenteral contraceptives. The removal of carbon 19 from testosterone changes the major hormonal effect from androgenic to progestogenic, but these "19-nor" steroids retain varying degrees of androgenic activity. (They can also have limited estrogenic activity, but this is insignificant at the low doses used for contraception.) Some of the 19-nortestosterone progestins are metabolized to other compounds (e.g., norethynodrel, ethynodiol diacetate, and lynestrenol to norethindrone), and some (levonorgestrel, desogestrel) are active unchanged. The lingering androgenic effects of 19-nor progestins are dose-related, opposed by estrogen, and are manifested metabolically (e.g., glucose tolerance, lipoprotein synthesis) and symptomatically (e.g., acne, weight gain). The effect of 19-nortestosterones on lipoproteins prompted the development of less androgenic compounds, but the obvious benefit of the new progestins (desogestrel, gestodene, norgestimate) is a reduction in the symptoms associated with the androgenicity of the older compounds. Mitigation of androgenic effects on lipoprotein and carbohydrate metabolism could have long-term benefits, especially for women who are at risk of arteriosclerotic vascular disease; however, these effects remain to be epidemiologically demonstrated.

Twelve years of clinical experience with an oral contraceptive containing 30 micrograms ethinyloestradiol and 150 micrograms desogestrel

The clinical experience with a combined oral contraceptive (COC) containing 150 micrograms desogestrel and 30 micrograms ethinylestradiol is reviewed. Fourteen clinical trials have been reported involving over 44,000 women for more than 190,000 cycles. None of the 17 pregnancies which occurred (overall Pearl Index 0.12) were due to method failure. The incidences of breakthrough bleeding and spotting after 6 treatment cycles varied from 0.1-6.0% and 2.8-11% of subjects, respectively, and at this time they were not significantly different from pretreatment in most trials. About 90% of subjects maintained regular cycles. The incidence of subjective side effects (approximately 5% for headache, 4% for breast tenderness, 2% for nausea) was low. No significant changes occurred in body weight or blood pressure. In all trials, the COC was well accepted and the rates of discontinuation were similar to those in other COC trials. Pharmacodynamic effects have been widely investigated. There were no significant changes in glucose metabolism or in haematological factors except for possibly minor increases in factors VII and X, fibrinogen and plasminogen. Over thirty studies of the effect of the COC on lipid metabolism have been published; significant increases occur in serum triglycerides, HDL-C and apoprotein A1. SHBG concentrations increase 2-3 fold with a consequent decrease in the levels of free testosterone. This effect can be particularly important therapeutically in women with hyperandrogenic skin disorders and 14 trials in women with these disorders have demonstrated significant clinical improvement with the COC. The findings from the various trials show the COC to be effective and acceptable with no adverse metabolic effects.

Clinical experience and pharmacological effects of an oral contraceptive containing 20 micrograms oestrogen

The performance of a new low-dose oral contraceptive (Mercilon) containing only 20 micrograms ethinyloestradiol combined with 150 micrograms desogestrel is reviewed. Eight multicentre clinical trials have been completed and provide information on 10,672 women studied over 73,477 cycles. The high efficacy of Mercilon was indicated by the finding that only 10 pregnancies were reported; nine of these occurred in women who omitted to take Mercilon on a number of days and only one in a woman who took all the tablets according to instructions. Cycle control was good; as with all oral contraceptives, the incidence of breakthrough bleeding and spotting was highest in the first treatment cycle and by the sixth treatment cycle the values were usually < 5% and < 7%. More than 80% of women had regular cycles. Side effects were few, the most common being headache, nausea and breast tenderness with incidences in the sixth treatment cycle of less than 2%, 6% and 6%, respectively. There were no significant changes in body weight or blood pressure. Pharmacodynamic investigations showed no adverse effects. Only 1 of 5 studies found an increased response to a glucose tolerance test compared to the pretreatment test. In 8 of 10 studies, serum HDL-C concentrations increased on treatment and this was associated with increases in apoproteins A1 and A2. Serum triglyceride levels also increased but no change occurred in serum cholesterol or LDL-C levels. Haematological factors were assessed in 8 studies and only minor changes were observed. Serum binding protein (SHBG, CBG, caeruloplasmin) concentrations increased and serum androgen levels decreased. Measurements of blood FSH, LH, oestradiol and progesterone indicated adequate inhibition of ovulation. Mercilon is the only oral contraceptive containing 20 micrograms ethinyloestradiol to have high efficacy, to have no adverse pharmacodynamic effects and, importantly, to produce an acceptable bleeding pattern not significantly different from that of oral contraceptives with a higher content of ethinyloestradiol.