Planned Parenthood experience with triphasil.
Triphasil, a low-dose combination oral contraceptive containing levonorgestrel and ethinyl estradiol, was tested in four Planned Parenthood clinics on 317 women between 18 and 34 years of age (mean, 23) for a total of 4,692 cycles, or 361 woman-years of usage. Approximately half these volunteers (165) were nulligravidas, and 309 (97.5%) were white. Despite instructions on proper tablet usage, there were 416 cycles (8.9%) in which one or more tablets were missed. Only one pregnancy occurred, in a cycle in which a total of four tablets was missed, for an uncorrected Pearl index of 0.28 pregnancies per 100 woman-years of usage. No pregnancy resulted from method failure, indicating a 100% efficacy rate for Triphasil when taken properly. The mean length of the menstrual cycle with Triphasil was 27.9 days; the mean length of menses, 4.4 days; and the mean latency period, 2.1 days. Menstrual flow was average in 64.1% of the subjects, light in 34.1%, heavy in 1.3% and variable in 0.5%. Amenorrhea during the tablet-free interval occurred in only 0.6% of the 4,692 cycles in which Triphasil was used. Breakthrough bleeding occurred in 6.9% of first cycles and 3.2% of total cycles; spotting, in 10.7% of first cycles and 4.4% of total cycles. Other symptoms that occurred with an incidence of greater than or equal to 1% were acne (1.0%), appetite increase (1.2%), breast discomfort (2.8%), breast enlargement (1.3%), gastrointestinal symptoms (1.7%), simple headache (1.4%) and nausea (1.1%). A total of 44 women (13.9%) discontinued treatment for medical reasons.(ABSTRACT TRUNCATED AT 250 WORDS)