Safety of a new oral contraceptive containing drospirenone.

New chemical entities must undergo rigorous, and preferably independent, safety and efficacy assessments before entry into the market. This is also true for oral contraceptives (OCs) given their extensive usage by healthy women and the safety concerns highlighted by the so-called 'third generation pill scare' in Europe a decade ago. This scare heightened patient and physician awareness of the increased risk of thromboembolic complications (mainly venous thromboembolism [VTE]) associated with OC use. Yasmin (ethinylestradiol 30 microg/drospirenone 3 mg [EE/DRSP]) is a novel OC that was demonstrated in clinical phase I-III studies to be highly effective in preventing pregnancy and to have a good safety profile. Nonetheless, clinical trials are not usually sufficiently powered to detect rare adverse events such as VTE to enable comparison with other OCs, which could allay fears and concerns about their inherent risks. Therefore, an extensive assessment of the VTE risk associated with EE/DRSP has been undertaken by reviewing data from the clinical development programme, postmarketing surveillance and spontaneous worldwide reporting, as well as information from other sources. Spontaneous worldwide reporting has revealed a VTE reporting rate of 5.1/100 000 women-years with EE/DRSP use. In contrast, 3-year interim results from a large, controlled, prospective postmarketing surveillance study suggest a VTE rate of 61/100 000 women-years for EE/DRSP, which is similar to the rates of 60/100 000 and 73/100 000 women-years for levonorgestrel-containing OCs and other OCs, respectively. When placed in context with potential biases and confounding factors that would inflate the perceived risk of VTEs with a novel OC, the VTE rate with EE/DRSP does not highlight any safety concerns. Furthermore, the risk of VTE with EE/DRSP or other OCs is far less than that associated with pregnancy and delivery (up to 800/100 000 women-years) or than other risks of daily living. Available data indicate that EE/DRSP is not associated with any increased risk of other serious adverse events such as hyperkalaemia, cardiac arrhythmia or birth defects. Nonetheless, caution should be exerted in prescribing EE/DRSP to women with conditions that predispose to hyperkalaemia.Overall, the safety data with EE/DRSP and other OCs indicate that these products have no negative impact on the risk of VTE (and other adverse events) in women who receive OCs for contraception.