Enhancing oral contraceptive success: the potential of new formulations

Reductions in oral contraceptive (OC) estrogen dose and the development of new progestins have resulted in formulations that maintain acceptable cycle control while improving safety. However, the potential safety benefits of low-estrogen doses may be offset by less acceptable cycle control. These observations have led to the development of 2 triphasic OC formulations containing norgestimate and desogestrel in combination with 25 microg ethinyl estradiol (EE). Both of these 25-microg EE triphasic OCs balance fewer estrogen-related side effects with good cycle control comparable to OCs containing higher estrogen doses. However, questions remain about the risk of venous thromboembolism associated with OCs containing desogestrel. A new monophasic 30-microg EE OC contains drospirenone, a spironolactone analogue with which there is limited experience. Although initial data with this OC are intriguing, product labeling highlights safety issues related to its antimineralocorticoid effects and the potential for hyperkalemia. Further experience with this formulation will determine its role in contraceptive practice.