Efficacy and side effects of immediate postcoital levonorgestrel used repeatedly for contraception

We Evaluated the efficacy and side effects of immediate postcoital administ ration of levonorgestrel 0.75 mg used repeatedly for contraception. A total of 295 healthy women with infrequent coitus were enrolled at G study sites . Each woman took levonorgestrel 0.75 mg by mouth immediately after interco urse during 6 months as her only method of contraception We collected data on side effects and acceptability and calculated the Pearl index failure ra tes over 133 woman-years of use by standard methods. The Pearl index failur e rate was 6.8 (95% CI 3.1-12.9) pregnancies per 100 woman-years of use. Th e overall probability of pregnancy per treated coital act was 1.4 per 1000. Approximately one-third of participants discontinued the study within 6 mo nths (mainly for bleeding problems). Menstrual complaints were reported by 70% of women. Other complaints included tin decreasing order) nausea, breas t tenderness, weakness, dizziness, headache, abdominal bloating, loss of li bido, depression, and vomiting. High dose levonorgestrel pills are unsuitab le for regular postcoital contraception. (C) 2000 Elsevier Science inc. All rights reserved.