A norgestimate-containing oral contraceptive: review of clinical studies

Despite the well-documented efficacy and safety of low-dose oral contraceptives, the development of newer formulations containing highly selective progestins with minimal or no androgenic activity has been a goal of pharmaceutical research. The efficacy and safety of norgestimate, a progestin with inherently low androgenicity, in combination with ethinyl estradiol, has been examined in several phase II and phase III clinical studies, and these are reviewed. Norgestimate/ethinyl estradiol has proved to be a low-dose oral contraceptive with high selectivity that provides the cycle control of older oral contraceptive formulations with comparable efficacy. Results of comparison studies between norgestimate/ethinyl estradiol and formulations containing norgestrel, a progestin with relatively greater androgenic activity, in combination with ethinyl estradiol, are reported for effects on lipid and lipoprotein levels and carbohydrate metabolism. Norgestimate/ethinyl estradiol consistently produced statistically significant increases in high-density lipoprotein cholesterol and improvement in the ratio of low-density lipoprotein cholesterol to high-density lipoprotein. In contrast, norgestrel/ethinyl estradiol produced statistically significant decreases in high-density lipoprotein cholesterol and potentially adverse changes in the low-density/high-density lipoprotein ratio. Phase II studies have confirmed that norgestimate/ethinyl estradiol has low androgenic activity and causes minimal effect on coagulation factors and carbohydrate metabolism.