Action of norethindrone on the premenstrual tension syndrome.

In preliminary studies rhesus monkeys received 2.5 mg of norethindrone daily during 21 days of each menstrual cycle over periods of 1-2 years. This was the equivalent of 25 mg daily for women. There was temporary suspension of ovulation but no permanent alterations in reproductive or menstrual functions. Following this preliminary study norethindrone was administered at a daily dose of .35 mg to 104 patients for the purpose of relieving the symptoms typical of premenstrual tension. Of these 46 patients had slight 20 moderate and 5 severe symptoms. Follow-up was for 165 menstrual cycles. In those with only slight symptoms 5.6% were reported to be worse. Improvement was noted in 66.9%. In 27.5% there was no change. In patients with moderate symptoms 67.5% were improved but none was made worse. In the 5 cases of severe premenstrual tension 37.5% were unchanged but in 62.5% there was marked relief. No worsening was reported. The possible factors responsible for the premenstrual tension syndrome may be alteration of estrogenic metabolism principally hyperestrogenism.