Contraception with norethindrone 0.35 mg administered continuously.
Microdose norethindrone (0.35 mg taken each day without interruption) was used as an oral contraceptive agent by 168 women for 4,264 months over a five-year span. Seven pregnancies occurred with regular use and two with irregular use, resulting in a drug-effectiveness rate of 1.9 and a use-effectiveness rate of 2.5 per 100 woman-years. Cycle length was variable. During the five years of study there was a tendency toward weight gain, but no definite trend in blood pressure changes was noticed; however, there were no comparable control groups for these latter two observations. Results of metyrapone tests done after 17 to 33 months of treatment were normal.
D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004341:Drug Evaluation; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D009640:Norethindrone / Q000008:administration & dosage* / Q000009:adverse effects; D011247:Pregnancy; D011275:Pregnancy, Unwanted
D009640:Norethindrone