Comparative evaluation of contraceptive efficacy of norethisterone enanthate 200 milligram injectable contraceptive given every 2 or 3 months
Et Al
Contraception 30(6): 561-574
1984
ISSN/ISBN: 0010-7824 Document Number: 407966
A total of 2388 subjects, 1181 for 60 .+-. 5-day and 1207 for 90 .+-. 5-day treatment regimen with norethisterone enanthate (NET OEN) 200 mg injection, were observed for 24 mo., constituting 28,513 woman-months. This clinical trial represents the largest clinical trial undertaken on NET OEN. NET OEN given at 60 .+-. 5-day intervals provided adequate contraceptive protection. As compared to the published studies elsewhere, higher method failures were seen during the first 6 mo. of NET OEN usage, when all women were receiving the drug at 60 .+-. 5-day intervals. The reasons for this discrepant observation in the present study cannot be explained. The higher method failures reported with 90 .+-. 5-day regimen were mainly during the 3rd mo. following the injection, suggesting reduced contraceptive efficacy of the drug during this period. Thin built women (body weight .ltoreq. 40 kg) were at higher risk of involuntary pregnancy. Disrupted menstrual pattern was the major reason for discontinuation ranging between 42-43 per 100 users at the end of 24 mo. Among these, amenorrhea was the commonest reason for discontinuation. No change in blood pressure was observed during contraceptive usage. The majority of NET OEN users did not show any change in body weight. The overall continuation rates with NET OEN were lower than those observed in similar conditions with Cu-T 200 mm2 IUCD.