An oral contraceptive. A 4-year study of norethindrone.

Abstract

Experience with norethindrone taken by 570 women over a 4-year period (1956-1960) is reported. The 570 patients who received norethindrone represented a total of 7194 patient-cycles and included a substantial number of long-term users. 6 unplanned pregnancies occurred 5 of which were definitely related to incorrect use of the method. There were 15 planned pregnancies. 56 of the patients reported the occurrence of nausea at one time or another. 87 patients had breakthrough bleeding or intermenstrual spotting. The incidence of missed periods was 6%. 89 patients reported an increase in libido during 128 cycles whereas 17 reported a decrease during 18 cycles. 28 mentioned soreness of the breasts during 36 cycles. 209 patients noted that their menstrual pain was diminished whereas 142 reported it to be increased. It is concluded that norethindrone given in a dose of 10 mg/day on 20 days of the menstrual cycle is very effective for contraception and can be prescribed for at least 2 years with assurance as to its probable safety.