Clinical evaluation of a new triphasic oral contraceptive: norgestimate and ethinyl estradiol.

The safety and efficacy of the triphasic oral contraceptive agent containing norgestimate and ethinyl estradiol were evaluated in a 12-month study of 661 women. Excellent contraceptive efficacy was achieved, with two pregnancies ascribed to product failure in a total of 6,511 treatment cycles. The life-table predicted pregnancy rate was 0.57 per 100 woman-years of use. The overall and theoretical Pearl indexes were 0.55 and 0.37, respectively. Good cycle control was maintained in patterns similar to those noted in previous studies. The incidence of dysmenorrhea and premenstrual syndrome was sharply reduced. Side effects reported were typical of those associated with use of low-dose oral contraceptive agents. Acceptability was high compared with agents used previously by the subjects. Total cholesterol did not change but high-density lipoprotein cholesterol was significantly elevated at 3 and 12 months. There were no clinically significant changes in the parameters of hematology or blood chemistry tested.