The risk of liver disorders in women prescribed cyproterone acetate in combination with ethinyloestradiol (Dianette): a nested case-control study using the GPRD

Purpose: To explore the risk of liver disorders associated with cyproterone acetate combined with ethinyloestradiol (CPA/EE). CPA/EE is licensed in the UK for the treatment of women with acne and hirsutism and is a treatment option for polycystic ovary syndrome (PCOS). It acts as a contraceptive also.

Methods: Using the General Practice Research Database, we conducted a cohort analysis and case-control study in women aged 15-39 with acne, hirsutism or PCOS to estimate the risk of liver disorders associated with CPA/EE.

Results: Compared with cases exposed to conventional combined oral contraceptives (COCs), the age-adjusted incidence rate ratio for liver disorders in women using CPA/EE was 1.7 (95%CI: 0.9,3.4) and compared with no use it was 1.5 (95%CI: 0.8, 2.8). In the case-control study, the adjusted odds ratio (OR) for liver disorders in women exposed to CPA/EE was 1.6 (95%CI: 0.7, 3.5) and 0.8 (95%CI: 0.5, 1.3) for exposure to conventional COCs, compared with no use. The risk of liver disorders in women prescribed CPA/EE was not significantly greater than that in women prescribed conventional COCs (OR: 2.1 [95%CI: 0.9, 4.8]).

Conclusion: Our results do not indicate an increased risk for liver disorders associated with CPA/EE use in women with acne, hirsutism or PCOS after adjusting for potential confounding. This may be due to lack of statistical power.