A CROSS-OVER STUDY OF 3 ORAL-CONTRACEPTIVES CONTAINING ETHINYLESTRADIOL AND EITHER DESOGESTREL OR LEVONORGESTREL

A randomised cross-over trial was performed to compare the pharmacodynamic actions of three low-dose oral contraceptives (OCs): Marvelon (150-mu-g desogestrel (DSG) + 30-mu-g ethinyloestradiol (EE)), Mercilon (150-mu-g DSG + 20-mu-g EE) and Microgynon (150-mu-g levonorgestrel (LNG) + 30-mu-g 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 All was increased by all three OCs but only the DSG OCs increased apoprotein Al. 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.