A randomized cross-over study comparing pharmacodynamic and metabolic variables of a new combiphasic and a well-established triphasic oral contraceptive.

In an open-label, randomized, cross-over study in 20 subjects, the short-term effects were investigated of Gracial (DSG/EE 7 x 25/40 micrograms/day + 15 x 125/30 micrograms/day) and Trigynon (LNG/EE 6 x 50/30 micrograms/day + 5 x 75/40 micrograms/day + 10 x 125/30 micrograms/day) on plasma concentrations of 17 beta-estradiol and progesterone as well as on carrier proteins (SHBG, CBG, ceruloplasmin), AT-III, carbohydrate metabolism (insulin, glucose, glycosylated proteins) and lipid metabolism (total cholesterol, triglycerides, phospholipids, HDL-C, LDL-C, HDL2-C, HDL3-C, HDL2-C/HDL3-C ratio, Apo A1, Apo B, Apo A1/Apo B ratio). Both preparations adequately and similarly inhibited ovulation in all subjects. Serum levels of carrier proteins were significantly higher with DSG/EE than with LNG/EE, whereas no between-group differences were observed with respect to fasting glucose and insulin, glycosylated proteins (mainly glycosylated albumin) and AT-III activity. DSG/EE showed significantly higher plasma levels than LNG/EE of estrogen-dependent lipid parameters such as triglycerides, HDL-C, HDL2-C, Apo A1, HDL2-C/HDL3-C ratio and Apo A1/Apo B ratio, whereas the levels of LDL-C and Apo B were significantly lower. Both oral contraceptive preparations were equally effective in suppression of follicular development, but combiphasic DSG/EE induced higher plasma levels of carrier proteins and higher plasma levels of potentially anti-atherogenic lipid parameters than did triphasic LNG/EE.