PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Norethindrone Enanthate”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1980

A randomized, single blind comparative trial of norethindrone enanthate and depo-medroxyprogesterone acetate in Bangladesh.

A randomized, single blind comparative trial of norethindrone enanthate (NET-ENT) and depo-medroxyprogesterone acetate (DMPA) was conducted in the Model Clinic, Decca, Bangladesh, to determine if there were differences in reported side effects, reasons for discontinuation and discontinuation rates of these two injectables. On all follow-up visits the proportion of women reporting no bleeding (amenorrhea) was higher for the DMPA clients compared to the NET-ENT clients. Concurrent with these findings, the proportion of women reporting irregular bleeding was consistently higher for the NET-ENT clients. Concurrent with these findings, the proportion of women reporting irregular bleeding was consistently higher for the NET-ENT clients compared to those receiving DMPA. By the fourth injection, less than 15% of the clients in both drug groups still reported having regular cyclic bleeding (4 of the 26 DMPA clients and 4 of the 28 NET-ENT clients). Five of the 133 women on DMPA and 6 of the 106 women on NET-ENT became pregnant while using the injectables. At the end of one year of follow-up, 14 of the 133 DMPA and 14 of the 106 NET-ENT clients were still continuing (came back for a fifth injection).

Adult↗
PubMed1991

[Pharmacokinetics of norethindrone enanthate 200 mg after intramuscular injection in 25 Chinese women].

Pharmacokinetic profile was studied in 25 healthy fertile Chinese female volunteers after im norethindrone enanthate (NET-EN) 200 mg. The results were compared with the data from British women in our previous paper. Following a single im NET-EN 200 mg, the times to reach peak levels of NET-EN and NET were 4.0 +/- 2.8 d and 5.4 +/- 2.0 d, and their peak values were 5.0 +/- 1.8 and 12.6 +/- 0.9 ng.ml-1, respectively. Mean elimination T1/2 of NET was significantly longer than that of NET-EN. Mean apparent elimination T1/2 were 14.8 +/- 3.8 d for and 11.4 +/- 5.7 d for NET-EN. The elimination rate of NET in Chinese women was significantly slower than that in British women. There was no significant ethnic difference in absorption kinetics of NET and NET-EN.

Adult↗
PubMed1980

Effects of progestin-estrogen combination and progestational contraceptives on pituitary gonadotropins, gonadal steroids and sex hormone-binding globulin.

The effects of three kinds of hormonal contraceptives on the levels of follicle-stimulating (FSH), luteinizing hormone (LH), estradiol, progesterone, testosterone, and sex hormone-binding globulins (SHBG) in three groups of normally menstruating women were analyzed. During the administration of a very low-dose combination of 150 micrograms of D-norgestrel and 30 micrograms of ethinylestradiol, a progressive suppression of LH, FSH, estradiol, and (to a lesser extent) testosterone levels was observed while progesterone stayed at levels found during the early follicular phase. SHBG levels in these subjects were within the normal range for women. Oral treatment with 0.5 mg of lynestrenol and the intramuscular administration of 200 mg of norethindrone enanthate produced a suppression of LH but not FSH in all cases. Estradiol levels showed peaks in the three women treated with lynestrenol and in half of those treated with norethindrone enanthate, suggesting follicular activity caused by the unsuppressed FSH stimulus; the subsequent elevation of progesterone in two subjects suggested some luteinization, although there was no evidence of an ovulatory surge of gonadotropins. The SHBG in four subjects treated with norethindrone enanthate fell within our normal range for men, and the mean serum testosterone levels fell 40% below the normal basal levels in these cases.

Adult↗
PubMed1990

Metabolism of levonorgestrel, norethindrone, and structurally related contraceptive steroids.

There is limited information on the metabolism of levonorgestrel, norethindrone and structurally related contraceptive steroids. Both levonorgestrel and norethindrone undergo extensive reduction of the alpha, beta-unsaturated ketone in ring A. Levonorgestrel also undergoes hydroxylation at carbons 2 and 16. The metabolites of both compounds circulate predominantly as sulfates. In urine, levonorgestrel metabolites are found primarily in the glucuronide form, whereas norethindrone metabolites are present in approximately equal amounts as sulfates and glucuronides. Of the progestogens structurally related to norethindrone, norethindrone acetate, ethynodiol diacetate, norethindrone enanthate, and perhaps lynestrenol, undergo rapid hydrolysis and are converted to the parent compound and its metabolites. There is no convincing evidence that norethynodrel is converted to norethindrone. Of the progestogens structurally related to levonorgestrel, it appears that neither desogestrel nor gestodene are transformed to the parent compound. However, there is evidence that norgestimate can be, at least partly, converted to levonorgestrel. Further studies on the metabolism of these progestogens are required before we can understand their mechanism of action.

Animals↗
PubMedDate not supplied

Salivary antipyrine half-life during injectable progestagen contraception.

Antipyrine pharmacokinetics were studied in 6 healthy women before and 2, 8 and 12 weeks after administering the injectable progestagen (progestin), norethisterone (norethindrone) enanthate 200mg intramuscularly. Additionally, antipyrine kinetics in 5 women who had previously used the injectable contraceptive for 8 to 14 months were compared with values obtained in 14 non-users. Antipyrine was measured in saliva using a spectrophotometric method, following an oral dose of 18 mg/kg bodyweight. In the 6 women studied prospectively the mean salivary antipyrine half-life was 14.91 +/- 1.5 hours (SEM) before administering the injection, and 13.56 +/- 0.73 at 2 weeks, 15.13 +/- 1.86 at 8 weeks and 15.21 +/- 2.46 hours at 12 weeks after the injection. The mean antipyrine half-life in the 5 long term users of injectable progestagen was 14.21 +/- 2.53 hours compared with 13.66 +/- 0.98 hours in non-users. The results of this study suggest that - in contrast to published data on combined oral contraceptives - neither short nor long term use of parenteral norethisterone enanthate in Indian women is associated with significant alterations in antipyrine clearance.

Adult↗
PubMed1983

7 alpha-Methylnorethindrone enanthate 10 beta-hydroperoxide: isolation and characterization.

10 beta-Hydroperoxy-7 alpha-methylnorethindrone 17-heptanoate (II), a product of allylic autoxidation of 7 alpha-methylnorethindrone enanthate (I), has been isolated and characterized. The synthesis of the hydroperoxide (II) from the 3-ethylene ketal of 7 alpha-methylnorethynodrel (III) was achieved. Esterification of alcohol (III), subsequent deketalization, and photochemical oxygenation resulted in the hydroperoxide (II). Reduction of the hydroperoxide (II) to the 10 beta-alcohol (VI) and acetylation of (II) to the 10 beta-acetoxyperoxide (VII) are described. A single subcutaneous injection of the compounds (II), (VI), and (VII) to rats failed to produce long term inhibition of fertility in contrast to the parent compound (I) which is at least five times more effective than norethindrone enanthate as measured by suppression of vaginal cornification and estrous cycles.

Animals↗
PubMed1980

Serum copper and zinc in hormonal contraceptive users.

There has been a growing awareness of possible alterations in the trace element profiles of hormonal contraceptive users and their consequences. A study of serum copper and zinc levels in users of combined estrogen-progestogen contraceptives and in users of injectable progestogen was undertaken. Use of combined estrogen-progestogen contraceptives resulted in a significant decrease in serum zinc levels within 3 days and an increase in serum copper levels within 10 days. In users of combined estrogen-progestogen contraceptives the magnitude and time of occurrence of the decrease in zinc levels and the increase in copper levels was unaltered by chemical composition, dosage, route of administration, and duration of use beyond 3 months. With injectable progestogen (norethindrone enanthate, 20 mg/month), a significant decrease in serum zinc levels occurred within 24 hours after injection. Serum copper levels were not altered. With injectable progestogen, the type of drug, the dosage, and the duration of use beyond the 1st month had no effect on the magnitude of the decrease in serum zinc levels.

20-alpha-Dihydroprogesterone↗
PubMed1982

A simple high-throughput enzymeimmunoassay for norethisterone (norethindrone).

A direct enzymeimmunoassay having the sensitivity required for determining norethisterone concentrations in small aliquots of plasma (10 microliter) has been developed. This assay featured a solid phase antiserum raised against a norethisterone-11 alpha-hemisuccinyl/bovine serum albumin conjugate. The antiserum was coupled to cyanogen bromide-activated magnetisable cellulose, and antibody-bound and free fractions were separated by a simple magnetic device. A norethisterone/horseradish peroxidase conjugate was used as the label; o-phenylenediamine/hydrogen peroxide being the substrate for colour development. The results obtained by this direct EIA, which allowed processing of at least 100 samples per day, were compared with those of a well-validated enzymeimmunoassay featuring solvent extraction and centrifugal separation of antibody-bound and free steroid; the results were in excellent agreement (n = 30; r greater than 0.99) suggesting the usefulness of the simple high-throughput procedure for processing the large sample numbers generated by field investigations and pharmacokinetic studies.

Centrifugation↗
PubMed1989

Long-acting steroidal contraception: an update.

Long-acting, injectable contraceptives first became available in the 1960s. It is currently estimated that almost 3.5 million women are now using depo-medroxyprogesterone acetate (DMPA); 800,000 are using norethindrone enanthate (NET-EN), and another few hundred thousand are using a variety of once-a-month injectables comprised of progestin plus estrogen. The advantages of injectable contraceptives are that they are highly effective, independent of coitus, easily administered, and they ensure regular contact with health services personnel. The last factor may be considered a disadvantage by some, since contact is more frequent than would be required for routine health services. The major disadvantage of the progestin-only formulations is disruption of normal menses, giving rise to unpredicted episodes of bleeding and spotting. With the once-a-month formulation, on the other hand, there are few discontinuations due to disruption of menses. For a long-acting method to be used longer than 6 months, it is desirable to choose an implant, since the method can be discontinued at will. The first implant system to be developed was Norplant, a set of six rubber capsules filled with levonorgestrel and implanted under the skin. The implant releases sufficient levels of medication to protect against pregnancy. For the first 5 years, the average failure rate was four or five per thousand users per year. The failure rate for women using standard oral contraceptives is approximately 20 to 50 per thousand. The most common side effect of the implant method is the disruption of the menstrual cycle, an effect that is particularly marked in the first month of use.(ABSTRACT TRUNCATED AT 250 WORDS)

Contraception↗
PubMed1982

Effect of injectable norethisterone oenanthate (Norigest) on blood lipid levels.

Lipid concentrations were measured in 74 blood samples from 61 women who had been using the injectable contraceptive Norigest (norethisterone oenanthate) for between 2 to 4-1/2 years. There were no significant changes in the concentrations of total cholesterol, total triglycerides and low density and very low density lipoprotein cholesterol but high density lipoprotein cholesterol was significantly reduced. The reduction in serum HDL-C levels was not correlated with either the serum norethisterone concentrations or the length of use of Norigest nor was it affected by obesity or smoking.

Adult↗
PubMed1984

Pharmacokinetics of different doses of norethisterone oenanthate.

Doses of norethisterone oenanthate of 300, 150, 100 and 50 mg were administered to four groups of subjects. Due to wide intersubject variations there were no statistically significant differences in the pharmacokinetic parameters for the different groups but there were significant correlations between the dose and the mean values for these parameters. There was little difference between the groups in the duration for which ovarian function was suppressed due to the inter-subject variation being greater than the inter-dose effect. The duration of the antifertility action of norethisterone oenanthate cannot be increased by increasing the dose above the standard 200 mg; however, with an injection interval of 60 to 70 days, it seems likely that the dose could be reduced to 150 mg.

Adult↗
PubMed1982

A clinical trial of norethisterone oenanthate (Norigest) injected every two months.

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.

Amenorrhea↗