Contraceptive efficacy and tolerability of chlormadinone acetate 2mg/ethinylestradiol 0.03mg (Belara®): Results of a post-marketing surveillance study

Objective: This post-marketing surveillance study aimed to investigate the contraceptive efficacy and tolerability of a combination tablet containing chlormadinone acetate 2mg and ethinylestradiol 0.03mg (Belara®) in daily gynaecological practice. A secondary aim was investigation of the changes in clinical signs of androgenisation. Design: 21 820 female patients were surveyed during a six-cycle period by 3600 gynaecologists throughout Germany. Results: Out of 21 820 patients, a total of 19 650 women (90.1%) completed the study. Chlormadinone acetate 2mg/ethinylestradiol 0.03mg had excellent contraceptive efficacy with an adjusted Pearl index of 0.076 (unadjusted Pearl index: 0.344), calculated from 125 634 cycles of exposure. Cycle control was good, with beneficial reductions in intracyclic bleeding (22.9% in cycle 1, 1.6% in cycle 6), amenorrhoea, severe withdrawal bleeding and dysmenorrhoea. At cycle six, only 1.2, 0.4 and 0.5% of all patients complained about spotting, breakthrough bleeding and amenorrhoea, respectively. At baseline, 69.9% of the women showed androgen-related skin disorders. After six cycles of chlormadinone acetate 2mg/ethinylestradiol 0.03mg, these disorders were improved in 86.5% of patients, including 28.5% who had complete resolution. Correspondingly, greasy or very greasy hair condition decreased from 47.0 to 13.6%. Chlormadinone acetate 2mg/ethinylestradiol 0.03mg was well tolerated; a total of two venous thromboembolic events (VTEs) occurred, and both patients recovered with appropriate treatment. Breast pain (3.6%) and migraine/headache (2.6%) were the most frequently reported adverse events. Conversely, these symptoms disappeared in most women (84.5 and 79.9%) who experienced them prior to chlormadinone acetate 2mg/ethinylestradiol 0.03mg treatment. Conclusions: These results support the reliable contraceptive efficacy, cycle stability and tolerability reported in previous clinical trials and confirm the marked antiandrogenic properties of chlormadinone acetate 2mg/ethinylestradiol 0.03mg.