Influence of nor-ethisterone enanthate on the structure of ovary, particularly corpus luteum.
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Biology↗
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Results for “Norethindrone Enanthate”
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A comparative study on the return to ovulation following chronic use of once-a-month injectable contraceptives.
A comparative study was undertaken involving 21 Mexican women who discontinued the use of medroxyprogesterone acetate 25 mg plus oestradiol cypionate 5 mg (Cyclofem) and norethisterone enanthate 50 mg plus oestradiol valerate 5 mg (Mesigyna) to assess the time required for the return to menses and ovulation. All subjects were exposed to once-a-month injectable contraceptives for two years and were followed for 120 days after the last injection. The urinary concentration of oestrone glucuronide and pregnanediol glucuronide was determined daily in all subjects beginning one month after the last injection. The results disclosed that ovulatory cycles were documented after 120 days of the last injection in six women of each studied group. Similar endometrial bleeding patterns were observed in both groups, indicating that the two drugs have alike pharmacokinetic and pharmacodynamic effects.
Adult↗
Phase I clinical trial of two contraceptive preparations. Norethisterone enanthate (NEN) and norethisterone acetate (NET).
A Phase I Clinical Trial was conducted in 20 fertile Cuban women using for contraception: Norethisterone Enanthate injectable (NEN) and Norethisterone Acetate minipill (NET). Women had daily blood sampling during a control cycle and during the second month of treatment with either drug. Discontinuation rate was very low (1/20). The preovulatory LH and FSH peaks were abolished in all treated women, basal levels remaining unchanged. The incidence of menstrual disorders as amenorrhea, spotting and inter-menstrual bleeding was greater in subjects using NEN than in those on NET. No pregnancy was reported. Blood pressure was unaltered. Renal, hepatic and thyroid function were unchanged. Cholesterol levels were unchanged and triglycerides significantly decreased with both preparations. Women on either NEN or NET underwent OGTT before and after 2 months treatment. In NEN group glycemia was unchanged but insulin levels increased significantly at 120 minutes. In NET group glycemia and insulin levels were significantly increased at all times during post-treatment OGTT. Both forms of Norethisterone were well accepted by this group of women despite menstrual irregularities. Significant changes were found in the group using NET with regard to carbohydrate metabolism.
Blood Glucose↗
Animal toxicity studies performed for risk assessment of the once-a-month injectable contraceptive Mesigyna.
Results from toxicity studies performed for risk assessment of the combined injectable hormonal preparation Mesigyna are reviewed. Both components of Mesigyna, i.e., estradiol valerate (E2Val) and norethisterone enanthate (NET-EN), have been thoroughly investigated as individual compounds and some limited toxicity data have been obtained for the combination. Most findings which were gathered in these studies from different animal species occurred in the gonads, accessory genital and endocrine organs and can be related to the known species-specific pharmacological activity of a typical estrogen or progestin, respectively. No additional or unexpected information which might indicate a possible estrogen/progestin interaction was gained from the administration of the combined preparation to animals. Based on the results from toxicity testing, there were no objections to the long-term therapeutic use of Mesigyna for hormonal contraception. The predictive value of the effects (including the tumorigenicity) observed in the common laboratory animals with regard to human safety is critically discussed, taking the vast amount of previous experience with hormonal contraceptives into consideration. The conclusion is drawn that there is no animal model for safety assessment of sex steroids that adequately represents the human situation. Quantitative extrapolations from animal toxicity findings to humans, therefore, are not possible. Especially, the value of long-term studies and of toxicity studies on estrogen/progestin combinations is put into question. Like endocrine pharmacology studies, the toxicity studies with these steroid hormones are useful for the characterization of the possible endocrine pharmacological profile only.
Animals↗
[Use and effectiveness of norethisterone enanthate for family planning in a rural area].
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Adolescent↗
[Norethisterone enanthate. Studies during the use of a long-acting parenteral contraceptive].
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Adrenal Glands↗
The effects of long-acting injectable contraceptives on carbohydrate metabolism.
Carbohydrate metabolism, as assessed by the intravenous glucose tolerance test (i.v.-GTT), was studied in 19 healthy, non-lactating women who received injectable contraceptives containing either medroxyprogesterone acetate (DMPA) (10 subjects) or norethisterone enanthate (Net-En) (9 subjects). Tests were made prior to treatment and at intervals over a period of 15 months thereafter. Results obtained indicate that carbohydrate metabolism is not impaired by either of the two progestogens, and neither pyruvate nor cortisol concentrations changed significantly over the period of observation. However, the insulin release in response to glucose loading underwent interesting alterations during treatment. These abnormalities returned promptly to normal after withdrawal of treatment.
Adult↗
Effect of norethisterone enanthate on the blood count and endometrial histology of Indian women.
Endometrial histology and the haematological indices were studied in women receiving 200 mg of norethisterone enanthate (NET-EN) at 60-day intervals for 24 months as a method of contraception. Significant elevations occurred in the haemoglobin concentration and red blood cell counts during one year of therapy, while eosinophil counts showed a transient increase at 4 months of trial. The changes in the haematological indices seem to be due to stimulation of the erythropoietic system by NET-EN and may also be attributable to diminished blood loss due to amenorrhoea during the course of therapy. The endometrial histology revealed proliferative glands at 2 months which turned quiescent at 6-12 months of NET-EN therapy. Long-term use of 18 months showed atrophic changes with few glands, narrow lumina and stromal oedema.
Blood Cells↗
Phase IV study of the injection Norigest in Pakistan.
A field study of the injectable contraceptive, norethisterone enanthate (NET-EN), was conducted in family planning clinics in Sind and Punjab provinces of Pakistan, to determine the acceptability and feasibility of providing NET-EN in government family planning clinics staffed by Family Welfare Visitors (FWVs). A total of 2147 women were recruited to the study, of whom approximately three-fourths had never previously used contraception. The overall discontinuation rate at one year was 78 per 100 women; the most common reason for discontinuation was bleeding disturbances, including amenorrhea, although returning to the clinic too late for an injection also accounted for a substantial proportion of the discontinuations. Given adequate training, FWVs were shown to be capable of providing NET-EN in family planning clinics, including managing the bleeding disturbances common with this method of contraception. No pregnancies were reported, demonstrating that the method is highly effective when used in a usual family planning clinic situation.
Adolescent↗
Estrogen-progestogen once-a-month injectable contraceptives and serum prolactin.
To assess the effect of hormonal monthly injectable contraceptives upon the serum values of immunoreactive prolactin (Prl), three groups of women of reproductive age exposed to different estrogen-progestogen injectable formulation for a minimum of one year were studied. The first group (n = 10) received dihydroxyprogesterone acetophenide 150 mg and estradiol enanthate 10 mg (DHPA/E2-EN), Group 2 (n = 21) received medroxyprogesterone acetate 25 mg and estradiol cypionate 5 mg (MPA/E2-C) and Group 3 (n = 19) was exposed to norethisterone enanthate 50 mg and estradiol valerate 5 mg (NET-EN/E2-V). A group of IUD users (n = 16) served as the control group. Serum Prl and 17 beta-estradiol (E2) concentration were determined in blood samples (0 and 15 min.) on days 0 (day of last injection), 10, 20 and 30 after last contraceptive injection. The results demonstrated a slight though not significant increase (p greater than 0.05) in serum Prl in the three experimental groups as compared with the IUD control group. This increase in Prl levels observed on day 10 post-last injection never exceeded the upper limits of the normal range (20 ng/ml). Overall, the data demonstrated that the chronic administration of these estrogen/progestogen once-a-month injectable contraceptives does not affect the Prl baseline secretion in women.
Adult↗
Cytokeratin 8, 18 and 19 in endometrial epithelium of Norplant and norethisterone enanthate injectable progestogen contraceptive users.
Cytokeratins 8, 18 and 19 are members of the cytoskeletal intermediate filament family found in all simple epithelia. Intermediate filaments are dynamic intracytoplasmic structures that can be influenced by a number of external factors. Norethisterone enanthate (NET-EN) is a long-acting progestogen contraceptive that has been found to arrest endometrial growth in the rat. Both Norplant and NET-EN cause bleeding problems among users which are responsible for > 50% of withdrawals with these methods. The aim of this study was to explore changes in the expression and distribution of cytokeratins 8, 18 and 19 in NET-EN- and Norplant-exposed endometrial epithelium which could be related to bleeding disturbances. Seven NET-EN and 37 Norplant endometrial biopsies were paraffin-embedded and stained immunohistochemically to evaluate cytokeratin expression and distribution. The results showed that women who had received NET-EN for 3-4 months had a cytokeratin distribution similar to that seen in the normal menstrual cycle. This is in contrast to endometrium from Norplant users in which cytokeratin expression was reduced and the epithelial cells were more rounded. No relationship between cytokeratin expression and breakthrough bleeding pattern was found. NET-EN and Norplant may act differently on endometrial epithelial cytokeratin.
Adult↗
A survey of different approaches to management of menstrual disturbances in women using injectable contraceptives.
This report summarises a survey of the management of menstrual disturbances occurring during injectable progestogen use (depot-medroxyprogesterone acetate, DMPA, and norethisterone enanthate, NET-EN) by 35 investigators from 20 countries with ongoing experience of these contraceptives. A wide range of approaches are described. The most frequently emphasised aspect of management is thorough pre-treatment counselling with further support and counselling at follow-up visits. Oestrogens in various forms are widely used for the treatment of prolonged, frequent or heavy episodes of bleeding, but nowadays are not usually used for the induction of withdrawal bleeding in women with amenorrhoea. Heavy or "severe" bleeding appears to be very uncommon and figures of 1-2% were frequently mentioned. Anecdotal information suggests that intramuscular doses or longer courses (14-21 days) of oral oestrogen, including the combined pill, are more likely to successfully stop an episode of bleeding than short courses. However, there are no hard data to show that a course of oestrogen treatment has any beneficial effect on long-term bleeding patterns. Nevertheless, temporary cessation of spotting or light bleeding may be sufficiently reassuring to the patient to ensure continued use of the method. There appears to be very little risk associated with the short-term oestrogen regimens currently used. Dilatation and curettage is almost never necessary to stop an episode of bleeding, but may occasionally be recommended for diagnostic reasons. It is clear that the bleeding disturbances associated with DMPA and NET-EN use are poorly understood and that urgent research is necessary to clarify pathophysiological mechanisms and improve management.
Amenorrhea↗
Long-term use of depot-norethisterone enanthate: effect on blood coagulation factors and menstrual bleeding patterns.
Fifty-six women using depot-norethisterone enanthate injections for contraception for 2 years or more were compared with a control group of 48 women not using hormonal contraception. No significant difference was found between the study group and controls for Factors VIIc and Antithrombin III. Factor Xc was reduced in women who had used the injections for over two but less than five years [controls: mean 90.3% SD31.2 vs users for 2-5 yr: 78.7% SD17.1, 95%CI difference in means -0.3, -22.9]. In the group using Net-En for five years or more, Factor Xc was significantly higher than in the control group, but only by 14% of the mean control value [users for over 5 yr: 103.2% SD15.2, 95%CI difference in means 3.1, 22.7]. Haemoglobin levels, red cell count and packed cell volume were higher in those using the injections than in the control group. Changes in the platelet count were not statistically significant. Twenty-three women using the injection agreed to keep menstrual diaries. Of these, 20 experienced amenorrhoea for more than two consecutive injection intervals (112 days). It is concluded that long-term use of norethisterone enanthate is not associated with any markedly deleterious effects on Factor VIIc, Xc, or antithrombin III or haemoglobin levels. Amenorrhoea of 4 months or more can be expected after two years of continuous use.
Adult↗
Acceptability of injectable contraceptives in Assiut, Egypt.
The present work was a randomized comparative study of two injectable progestogen-only contraceptives. The first group (200 subjects) received 150 mg of depotmedroxyprogesterone acetate (Depoprovera) every 84 +/- 7 days and the second (200 subjects) received 200 mg of norethisterone enanthate (Noristerat) every 56 +/- 7 days. Acceptors of injectable contraceptives in Assiut, Egypt, were mainly women looking for fertility termination. Menstrual disruption was the main side effect among both treatment groups. Amenorrhoea was the commonest menstrual complaint and was the main reason for discontinuation in both groups. Only one pregnancy occurred during NET-EN use; two more pregnancies occurred, one in each of the two groups but there were indications that conception preceded the first injection. Menstrual irregularities were generally more frequent with DMPA users. However, DMPA had better one-year continuation rates than NET-EN (68.8 +/- 3.5 and 57.1 +/- 3.6 per 100 women, respectively).
Adolescent↗
Return to ovulation following the use of long-acting injectable contraceptives: a comparative study.
A comparative study was undertaken in twenty-four Mexican women who discontinued the use of depo-medroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) to assess the time required for the return to menses and ovulation. All subjects were exposed to long-acting injectable contraceptives for at least one year, and were followed prospectively. Serum progesterone levels were determined weekly in all subjects beginning 3 months after the last progestogen injection. Mean time to return to ovulation occurred significantly earlier (p less than 0.001) after NET-EN (2.6 months) as compared with DMPA (5.5 months). No correlation between the return to ovarian function and the duration of steroid exposure was found. The overall data was interpreted as demonstrating a clear-cut difference between the two long-acting progestogens in terms of ovulation suppression.
Adult↗
Studies on some enzymes and sialic acid during progestational contraceptive therapy.
Injectable progestogen, norethisterone enanthate (NET-EN, 200 mg/ml at 60-day intervals), was administered to one-hundred-fifty women for two years as a method of contraception. Blood levels of acid phosphatase (ACP), alkaline phosphatase (AP), glutamate pyruvate transaminase (GPT), glutamate oxaloacetate transaminase (GOT), acetylcholinesterase (AChE) and sialic acid were determined in all the subjects to ascertain whether NET-EN therapy causes any adverse metabolic effect or damage to the functional status of the liver. NET-EN contraception did not alter the liver function enzymes, but there is a significant increase (P less than 0.001) in AChE activity after two years. Serum sialic acid level showed a transient increase up to one year, which however returned to control level later. The mechanism responsible for these changes and whether the rise in sialic acid and AChE activity are related to any pathological condition remain unclear at this stage.
Acetylcholinesterase↗
Effect of long-acting progestagen-only injectable contraceptives on carbohydrate metabolism and its hormonal profile.
Two groups, each composed of 20 women, who used depomedroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) injectable contraceptives were investigated for changes in 75-g OGTT and in the fasting and two-hour post oral glucose load (2-hours) levels of serum insulin, growth hormone, glucagon, cortisol and blood pyruvate. Samples were taken before and 3, 6 and 12 months after use of injectables. DMPA and NET-EN caused significant changes in mean blood glucose and pyruvate and in mean serum insulin, growth hormone and glucagon, but not in mean fasting cortisol. Changes with NET-EN started after 3 months, became maximal after 6 months and reverted to normal after 12 months of use, due to more frequent administration during the first 6 months of use (every 60 +/- 5 days) and to more spacing of the injections (every 84 +/- 5 days) after that. Changes with DMPA started after 3 months, and increased with the duration of use to become maximal after 12 months. Maximal changes were similar with DMPA and NET-EN and consisted of: a significant increase in fasting blood glucose and pyruvate and serum insulin; a significant increase in 2-hour blood glucose and pyruvate, serum insulin, growth hormone and glucagon. Although significant changes in blood glucose levels occurred with both DMPA and NET-EN, yet they did not reach the lower cut-off levels for impaired glucose tolerance in any user. With the same spacing of injections, i.e. every 84 +/- 5 days for NET-EN and every 90 +/- 5 days for DMPA, the effects on various parameters studied were less with NET-EN.
Blood Glucose↗
[Two years' clinical experience with norethisterone enanthate as a prolonged-action injectable contraceptive].
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Amenorrhea↗