A pilot efficacy study with a single-rod contraceptive implant (Implanon (R)) in 200 Indonesian women treated for <= 4 years

In this 4-year open-label, noncomparative, single-center pilot efficacy stu dy, the contraceptive efficacy, safety, bleeding pattern and acceptability of Implanon(R) was studied in 200 sexually active women of proven fertility in Indonesia. All subjects received the single-rod subdermal implant Impla non, which contains 68 mg etonogestrel (3-keto-desogestrel), with an initia l release rate of 67 mu g etonogestrelday. Contraceptive efficacy was analy zed by calculation of the pregnancy rate, bleeding patterns were determined by the 90-day reference period method, and acceptability by the discontinu ation rate. No in-treatment pregnancies were reported during 658.4 women-years of expos ure, resulting in a Pearl Index of 0.0 (95% CI 0.0-0.6). The overall bleedi ng pattern was acceptable, with no discontinuations because ed irregular bl eeding. Incidence of irregular bleeding was highest during the first two re ference periods and decreased thereafter. Amenorrhea was experienced by 7%- 12% of subjects during years 1 and 2, by 5%-7% during year 3, and by 2%-5% during year 4, with one discontinuation because of amenorrhea. No clinicall y significant changes were reported for systolic and diastolic blood pressu re, body mass index, and hemoglobin level. Three adverse experiences were r elated to treatment and resulted in discontinuation (two headaches and one dyspnea). One difficult implant removal was reported. In conclusion, this pilot efficacy study indicates that Implanon provides e xcellent contraceptive reliability and an acceptable bleeding pattern. Over all safety and acceptability are good, as suggested by the low incidence of adverse experiences and the low discontinuation rate. (C) 1999 Elsevier Sc ience Inc. All rights reserved.