The drospirenone (DRSP)-only pill: clinical implications in the daily use.

Objectives: Progestins used in contraception are either components of combined hormonal contraceptives or are used as a single active ingredient. Progestins are highly effective in long-term contraception and have a very good safety profile with very few contraindications.

Methods: An oestrogen-free ovulation inhibitor POP has been authorised in the USA and the EU. It contains 4 mg of drospirenone (DRSP). The hormone administration regimen of 24 days followed by a 4-day hormone-free period was chosen to improve bleeding control and to maintain oestradiol concentrations at early follicular- phase levels, preventing oestrogen deficiency.

Results: Clinical trials have demonstrated high contraceptive effectiveness, a very low risk of cardiovascular risk events and a favourable bleeding pattern. Due to the long half-life of DRSP (30-34 h), the effectiveness is maintained even in case of a forgotten pill on a single occasion. Studies involving deliberate 4 days in one cycle 24-hour delays in taking a pill have demonstrated that ovulation inhibition is maintained if a single pill is missed.

Conclusions: This review article will describe the clinical impact in the daily use of the 4 mg DRSP only pill and the resulting data on the effectiveness and safety of this hormonal contraceptive.