norethindrone-enanthate and Body-Weight

Norethisterone enanthate (NET-EN) 50 mg combined with estradiol valerate (EV) 5 mg was studied as a once-a-month injectable contraceptive with regard to effectiveness, cycle control, adverse events and acceptability. In eight Family Planning Centres from five Latin American countries, 931 fertile women were followed-up for a period of 36 months, providing a total of 15,787 woman-months of experience. Only one pregnancy occurred: in the first treated month a few days before the second injection (failure rate 0.08 per 100 woman-years). Under treatment, the first cycle was drastically shortened in most cases, but thereafter cycles tended to recover to pre-treatment patterns. There was a significant decrease of hypermenorrhoea and dysmenorrheic cycles. Intracyclic bleeding and spotting appeared in 1.8% and 2.2%, respectively, and amenorrhea in 2.8% of cycles. The incidence of other adverse events was very low with the exception of weight gain of more than 2 kg (36.8%). The continuation rate at 12 months was 64.7%, at 24 months 31.0% and at 36 months 20.4%. The cumulative discontinuation rate due to bleeding problems was 6.1% and 7.2% due to adverse events at 36 months. The treatment was shown to be a highly effective contraceptive method that offers fairly good cycle control, good tolerance and a continuation rate that makes it suitable for use in family planning programmes in the Latin American area.

Topics: Amenorrhea; Body Weight; Contraceptive Agents, Female; Estradiol; Female; Humans; Injections; Latin America; Norethindrone; Pregnancy; Uterine Hemorrhage

Growth, development and health of infants whose mothers used progestogen-only contraceptives during lactation were examined in a prospective, non-randomized study carried out in seven centres in five countries (Egypt, Thailand, Kenya, Chile and Hungary). The results on growth are reported here. Breastfeeding women requesting effective contraception were admitted to the study at six weeks postpartum. Infants of acceptors of progestogen-only methods (pill, DMPA, NET-EN or NORPLANT implants) and non-hormonal methods (IUD, barrier methods or sterilization) formed the study groups. The follow-up was at monthly intervals until the end of the first postpartum year. Participating in the study were 2466 mother-infant pairs. The mean duration of exclusive breastfeeding varied from 68 to 159 days, but did not differ significantly between study groups within centres. In anthropometric measures (weight, arm circumference and triceps skinfold), the mean rates of change varied over time as expected, and across the centres. However, there were very few statistically significant differences in these rates of change between groups within centres. Since a large number of statistical comparisons were made, and there was no consistency either across centres, over time, or in the direction of the differences, we conclude that in this study, the progestogen-only contraceptives used during lactation did not adversely affect infant growth.

Topics: Adolescent; Adult; Anthropometry; Body Weight; Child Development; Chile; Contraceptive Agents, Female; Drug Implants; Egypt; Female; Humans; Hungary; Infant; Kenya; Lactation; Levonorgestrel; Medroxyprogesterone Acetate; Norethindrone; Pregnancy; Progestins; Prospective Studies; Thailand

A Phase II multicentric study was carried out to compare the different contraceptive treatment schedules of the monthly injectable consisting of norethisterone oenanthate (NET OEN) 50 mg either given alone or in combination with estrogen esters, 2.5 or 5 mg of estradiol valerate (E2 Val.) or estradiol cypionate (E2 Cyp.). A total of 364 women were observed for 1686 months of use. Analysis of the bleeding pattern data indicated that NET OEN 50 mg when given alone gave rise to delayed cycles and/or amenorrhoea. However, the addition of estrogen esters in a dose of either 2.5 or 5 mg provided significantly better bleeding patterns. Of the different treatment schedules investigated, the combination of NET OEN 50 mg with E2 Val. 5 mg provided more consistent and better cycle control. These findings however need further validation on a larger study sample.

Topics: Adult; Amenorrhea; Blood Pressure; Body Weight; Clinical Trials as Topic; Contraceptive Agents, Female; Estradiol; Female; Humans; Injections; Menstruation; Menstruation Disturbances; Norethindrone; Oligomenorrhea; Random Allocation; Time Factors

A total of 2388 subjects, 1181 for 60 +/- 5-day and 1207 for 90 +/- 5-day treatment regimen with norethisterone oenanthate (NET OEN) 200 mg injection, were observed for 24 months, constituting 28,513 woman-months. This clinical trial represents the largest clinical trial undertaken on NET OEN. The observations indicated that NET OEN given at 60 +/- 5-day intervals provides adequate contraceptive protection. However, as compared to the published studies elsewhere, higher method failures were seen during the first six months 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 third month following the injection, suggesting reduced contraceptive efficacy of the drug during this period. Thin build women (body weight less than or equal to 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 months. Amongst these, amenorrhoea 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.

Topics: Adult; Body Weight; Clinical Trials as Topic; Contraceptive Agents, Female; Drug Administration Schedule; Female; Fertility; Humans; India; Injections, Intramuscular; Norethindrone; Pregnancy; Risk

A multicentre phase III clinical trial has been undertaken to compare norethisterone enantate (NET-EN) given by two different treatment regimens and depot-medroxyprogesterone acetate (DMPA). After 18 months of observation, preliminary findings are reported for 1,589 women who received DMPA 150mg every 90 days; 790 women who received NET-EN 200mg every 60 days; and 796 women who received NET-EN, 200mg every 60 days for 6 months, then 200mg every 84 days. The overall discontinuation rates per 100 women were similar for all three treatment groups over the 18 months observation (61.8 - 63.5 per 100 women). The discontinuation rates for bleeding problems and for personal reasons were also similar for all three treatment groups. However, terminations due to amenorrhoea were significantly higher among DMPA users (12.1 and 17.4 per 100 women at 12 and 18 months) as compared with both NET-EN groups (6.8 - 8.2 per 100 women at 12 months and 10.4 - 10.9 per 100 women at 18 months). The only significant difference in pregnancy rates observed between the three groups was a higher rate at 18 months among NET-EN (84 days) users (1.6 per 100 women), as compared with DMPA users (0.2 per 100 women). There was no overall significant difference between the two NET-EN groups, although between the 6 and 18 month's follow-up when the two NET-EN regimens diverged, the NET-EN (84 days) users' pregnancy rate rose significantly, whereas in the NET-EN (60 days) group the pregnancy rate did not change. There was a significantly higher weight gain in those subjects using NET-EN at 60-day intervals compared with those using it at 84-day intervals.. A multicenter phase 3 clinical trial compared norethisterone enanthate (NET-EN) given by 2 different treatment regimens and depot-medroxyprogesterone acetate (DMPA). After 18 months of observation, preliminary findings are reported for 790 women who received NET-EN 200 mg every 60 days; for 796 women who recieved NET-EN every 60 days (200 mg) for 6 months, then 200 mg every 84 days, and for 1589 women who received DMPA 150 mg every 90 days. Overall discontinuation rates and discontinuation for bleeding and personal reasons were similar for all 3 groups after 18 months observation (61.8-63.5/100 women). Terminations due to amenorrhea were significantly higher among DMPA users (12.1 and 17.4/100 women at 12 and 18 months) than among both NET-EN groups (6.8-8.2/100 women at 12 months and 10.4-10.9/100 women at 18 months). The only significant difference in pregnancy rates observed among the 3 groups was a higher rate at 18 months among NET-EN (84 days) users (1.6/100 women), than among DMPA users (0.2/100 women). There was no overall significant difference between the 2 NET-EN groups, although between the 6 and 18 month follow-ups when the 2 NET-EN regimens diverged, the NET-EN (84 days) users' pregnancy rates rose significantly, whereas in the NET-EN (60 days) group, the pregnancy rate did not change. Weight gain was significantly higher in those subjects using NET-EN at 60 day intervals than at 84-day intervals.

Topics: Amenorrhea; Body Weight; Clinical Trials as Topic; Contraceptive Agents, Female; Delayed-Action Preparations; Drug Administration Schedule; Female; Humans; Injections, Intravenous; Medroxyprogesterone; Medroxyprogesterone Acetate; Norethindrone; Pregnancy; World Health Organization

A clinical trial was carried out in which Norigest (200 mg norethisterone oenanthate) was administered by intramuscular injection every 56 days into 383 women studied for 5,521 woman-months of use. No pregnancies occurred. Continuation rates at the end of one, two and three years were 76.6%, 63.7% and 33.8%. Only minor side-effects were recorded. After one year of use, 20.1% women had gained more than 2 kg in weight and 14.8% had lost more than 2 kg. There was marked disruption of the menstrual pattern and irregular bleeding was the major cause of discontinuation. In 38% of the injection intervals analysed, women were amenorrhoeic. Norigest proved an effective and acceptable method of fertility control.

Topics: Amenorrhea; Blood Pressure; Body Weight; Clinical Trials as Topic; Contraceptive Agents, Female; Drug Administration Schedule; Female; Humans; Injections, Intramuscular; Menstruation; Norethindrone

Marmosets are used as preclinical model in reproductive research. In contrast to other primates, they display short gestation times rendering this species valid for exploration of effects on fertility. However, their peculiar endocrine regulation differs from a those of macaques and humans. We subjected male marmosets to previously clinically tested hormonal regimens that are known to effectively suppress spermatogenesis. Beside a control group, seven groups (each n=6) were investigated for different periods of up to 42 months: regimen I, (four groups) received testosterone undecanoate (TU) and norethisterone enanthate (NETE); regimen II, (two groups) received TU and NETE followed by NETE only; and regimen III, (one group) received NETE only. Testicular volume, cell ploidy and histology, endocrine changes and fertility were monitored weekly. TU and NETE and initial TU and NETE treatment followed by NETE failed to suppress spermatogenesis and fertility. Testicular volumes dropped, although spermatogenesis was only mildly affected; however, testicular cellular composition remained stable. Serum testosterone dropped when NETE was given alone but the animals remained fertile. Compared with controls, no significant changes were observed in sperm motility and fertility. Administration of TU and NETE affected testicular function only mildly, indicating that the regulatory role of chorionic gonadotrophin and testosterone on spermatogenesis is obviously limited and testicular function is maintained, although the endocrine axis is affected by the treatment. In conclusion, marmosets showed a different response to regimens of male contraception from macaques or men and have to be considered as a problematic model for preclinical trials of male hormonal contraception.

Topics: Animals; Antispermatogenic Agents; Body Weight; Callithrix; Chorionic Gonadotropin; Epididymis; Fertility; Male; Models, Animal; Norethindrone; Organ Size; Pituitary Gland; Ploidies; Sperm Motility; Testis; Testosterone

Prostate size and function are regulated by testosterone. However, the progesterone receptor is expressed in the primate prostate. Progestins affect the prostate by endocrine suppression, but can also act directly. Examining the role of progestins, we studied the effects of norethisterone (NET) on testosterone undecanoate (TU)-induced prostate growth in castrated macaques.. Two groups (n = 6 for each group) received TU every 9 weeks. Using a crossover setting, group I received norethisterone enanthate (NETE) 3 times at 3-week intervals, while group II received placebo. After 9 weeks, placebo was administered to group I, and group II received NETE.. In group II, the prostate grew under TU and placebo over the first period. In group I, coadministered with NETE, the increase was lower. After the crossover, prostates of animals previously treated with NETE did not increase to normal values under placebo. Prostates of animals treated with TU and placebo in the first period shrank following NETE administration after the crossover. The long half-life of NET can explain the lack of a TU effect on animals coadministered with NETE after the crossover.. Pre- and coadministration of NET reduces testosterone-induced prostate growth with possible implications for the treatment of benign prostate hyperplasia and hormonal male contraception.

Topics: Animals; Biomarkers; Body Weight; Drug Administration Schedule; Hematocrit; Hormone Replacement Therapy; Macaca fascicularis; Male; Norethindrone; Orchiectomy; Organ Size; Progestins; Prostate; Testosterone; Time Factors

Weight gain is commonly reported as a side effect of hormonal contraception and can lead to method discontinuation or reluctance to initiate the method. The purpose of this study was to investigate weight change in adolescent (aged 15-19 years) users of depot-medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN), combined oral contraceptives (COCs) and discontinuers of these methods as compared to nonusers of hormonal contraception.. This longitudinal study recruited initiators of DMPA (n=115), NET-EN (n=115), COCs (n=116) and nonusers of contraception (n=144). Participants were followed up for 4-5 years, and details of current contraceptive method, including switching, discontinuing and/or starting hormonal methods were documented at each 6-monthly visit. Women were classified according to their contraceptive histories on completion of the study, and injectable users were combined into one group for analysis. Height, weight and self-reported dieting were recorded at each visit.. There was no difference in mean age or weight between the groups at baseline. Women using DMPA or NET-EN throughout, or switching between the two, had gained an average of 6.2 kg compared to average increases of 2.3 kg in the COC group, 2.8 kg in nonusers and 2.8 kg among discontinued users of any method (p=.02). There was no evidence of a difference in weight gain between women classified as nonobese or classified as overweight/obese in any of the four study groups at baseline.. There is fairly strong evidence that adolescent contraceptive hormonal injectable users appear to gain more weight than COC users, discontinuers and nonusers of contraception.

Topics: Adolescent; Body Mass Index; Body Weight; Contraception Behavior; Contraceptives, Oral, Combined; Female; Humans; Longitudinal Studies; Medroxyprogesterone Acetate; Norethindrone; Prospective Studies; Weight Gain; Withholding Treatment; Young Adult

Norethisterone enanthate (NETE) is evaluated in trials of hormonal male contraception. It has been speculated that progestins may exert their contraceptive effects not only by suppressing gonadotropins but also by direct effects on male organs. NETE was given to monkeys in which endogenous gonadotropin secretion was suppressed by a gonadotropin releasing hormone (GnRH) antagonist, and replaced by human follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG). If NETE has a direct effect on spermatogenesis and/or epididymal function, some changes in testicular histology, sperm motility and/or morphology should occur soon after exposure to NETE.. Fifteen adult intact male monkeys were grouped and treated for a 38-day period. Group I received GnRH antagonist, FSH, hCG and NETE while group II received a regime identical to group I without NETE and group III received only NETE and vehicle. Ejaculates, body weight, testicular biopsies and volume, and hormones were evaluated.. There was a similar pattern of serum FSH and testosterone in groups I and II. Testicular volume and the proportion of tubuli exhibiting spermatids was significantly decreased in group III. There were no significant differences between group I and group II in any parameters measured. The forward progression of sperm was not affected by NETE treatment. The consistently low percentages of grade c sperm indicated no sign of hyperactivation. No changes in the gross morphology of the acrosome were detected.. Short-term NETE treatment has neither a direct effect on the testis nor on the epididymis in this nonhuman primate model and its contraceptive effects appear to be exerted exclusively through gonadotropin suppression.

Topics: Animals; Body Weight; Chorionic Gonadotropin; Contraceptive Agents, Male; Epididymis; Follicle Stimulating Hormone; Gonadotropin-Releasing Hormone; Macaca fascicularis; Male; Norethindrone; Sperm Count; Spermatids; Spermatogenesis; Testis; Testosterone

Plasma norethindrone (NET) and progesterone were estimated by radioimmunoassay in seven Indian women after intramuscular administration of 20 mg NET enanthate. One subject had intermenstrual bleeding throughout the cycle. Out of the six subjects considered for analysis, three subjects showed ovulation suppression, two had delayed ovulation and the remaining one exhibited normal ovulatory pattern. Post-peak average plasma NET values ranged from 1.0 to 2.1 ng/ml. These values showed a significant positive correlation with the anthropometric indices such as body weight and mid-arm-circumference. The subjects with lower anthropometry showed exponential decline of plasma NET. A possible role for nutritional status of an individual in drug disposition is indicated from this study.

Topics: Adult; Anthropometry; Body Weight; Female; Humans; India; Injections, Intramuscular; Norethindrone; Ovulation; Progesterone