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

Abstract

A randomised cross-over trial was performed to compare the pharmacodynamic actions of three low-dose oral contraceptives (OCs): Marvelon (150 micrograms desogestrel (DSG)+ 30 micrograms ethinyloestradiol (EE)), Mercilon (150 micrograms DSG + 20 micrograms EE) and Microgynon (150 micrograms levonorgestrel (LNG) + 30 micrograms EE). None of the OCs produced any significant changes in serum cholesterol, LDL-C and apoprotein B. Triglycerides were increased by the desogestrel OCs but not by Microgynon. The latter however increased the glucose and insulin responses to a glucose tolerance test whereas Marvelon and Mercilon had no effect. HDL-C increased with Marvelon, was unchanged with Mercilon and was decreased with Microgynon. Apoprotein AII was increased by all three OCs but only the DSG OCs increased apoprotein AI. All OCs produced similar increases in caeruloplasmin but the increase in SHBG was much greater with Marvelon and Mercilon than with Microgynon. Testosterone was reduced more with Microgynon than with the DSG OCs. Many of the changes reflect the strong anti-oestrogenic action of LNG on metabolic parameters compared to DSG. Except for the effect on HDL-C, there was little difference between Marvelon and Mercilon on metabolic parameters and this complements the findings from large-scale clinical trials of the two OCs. Mercilon, therefore provides a very satisfactory alternative to Marvelon.

PIP: 12 healthy volunteers attending the family planning clinic at Shanghai, First Maternity and Infant China, Hospital, enrolled in the study, Oral contraceptives (OCs) were prescribed: Marvelon (150 mcg of desogestrel--DSG), Mercilon (150 mcg of DSG), and Microgynon (150 mcg of levonorgestrel--LNG). The patients were divided into 6 groups of 2 persons each in a randomized cross-over study. OCs were taken on day 6 of the cycle up to day 21, then stopping for 7 days. Each OC was used for 3 months. During the pretreatment cycle between days 6 and 9 of the follicular phase and 21 and 22 of the luteal phase a blood sample was taken after fasting for determination of lipids, sex hormone binding globulin (SHGB), ceruloplasmin, and testosterone. After glucose loading, significant increases of glucose and insulin occurred at 1, 2, and 3 hours during treatment with Microgynon only. The ratio for total areas of insulin to glucose did not change significantly nor did glycosilated hemoglobin A1 levels. Serum triglyceride concentrations increased significantly for both Marvelon (27%-43%) and Mercilon (29-40%). Serum high density lipoprotein (HDL) cholesterol concentrations were significantly elevated with Marvelon but less so with Mercilon, while HDL-C decreased significantly with Microgynon. The serum low density lipoprotein (LDL) cholesterol changes were not significant, but LDL-C concentrations declined with DSG formulations and increased with Microgynon. Apoprotein A1 and A2 increased significantly for both Marvelon and Mercilon. Apoprotein A2 increased with Microgynon. Serum SHBG increased markedly with Marvelon (335-380%). Serum testosterone concentrations decreased significantly (33.2-40.4% with Microgynon) and so did ceruloplasmin values. The antiestrogenic effect of strong LNG in Microgynon produced significant metabolic changes. The effect of 30 mcg EE in Marvelon and 20 mcg EE of Mercilon was equal.