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At least 19 recordsLinked to original sources
PubMed1991

Metabolism of norgestimate by human gastrointestinal mucosa and liver microsomes in vitro.

The metabolism of the progestogen oral contraceptive norgestimate has been studied in vitro using human intestinal mucosa and human liver microsomes. Metabolites have been separated using radiometric high-performance liquid chromatography (HPLC) and identified by co-chromatography with authentic standards and by mass spectrometry. Histologically normal colon was obtained from 6 patients undergoing various resections and the mucosa mounted between 2 perspex (Ussing) chambers. 2 h after addition of [3H]norgestimate to the mucosal chamber, more than 95% of the radioactivity was present in that chamber. Metabolite analysis showed 38.1 +/- 11.6% (mean +/- SD; n = 8) of drug present was norgestimate, 49.2 +/- 14.5% as 17-deacetyl norgestimate and 8.1 +/- 4.5% as conjugated metabolites. Small amounts of 3-keto norgestimate, norgestrel and uncharacterized metabolites were found. Norgestimate was also metabolized by stomach tissue with 17-deacetyl norgestimate again being the main metabolite found. Microsomes were prepared from 6 human livers. Metabolism was studied over a 5 h time-course in the absence and presence of NADPH. Deacetylation to 17-deacetyl norgestimate took place in the absence of the cofactor. In the presence of NADPH, after 5 h incubation only 30.5 +/- 14.6% (mean +/- SD) of steroid present was norgestimate. The major metabolite formed was 17-deacetyl norgestimate which accounted for 39.3 +/- 20.5%. Less than 2% was present as 3-keto norgestimate but 10.0 +/- 2.3% was identified as norgestrel and 15.5 +/- 8.9% as uncharacterized metabolites. We also examined the microsomal breakdown of [3H]17-deacetyl norgestimate. This was NADPH and oxygen dependent. Norgestrel and other metabolites were formed. This study has demonstrated that norgestimate is rapidly deacetylated by both gut wall and liver. The deacetylated metabolite can then be further metabolized.

Chromatography, High Pressure Liquid↗
PubMed1990

Pharmacologic and pharmacokinetic characteristics of norgestimate and its metabolites.

Biotransformation, pharmacologic, and pharmacokinetic studies of norgestimate and its metabolites indicate that 17-deacetyl norgestimate, along with the parent drug, contributes to the biologic response. The postulated metabolic pathway, which is based on the identification of urinary products had indicated that three metabolites of norgestimate, 17-deacetyl norgestimate, 3-keto norgestimate, and levonorgestrel, might participate in the response. The pharmacologic evaluation of these metabolites demonstrates that only 17-deacetyl norgestimate has a pharmacologic profile consistent with that of norgestimate, and significant concentrations of this metabolite have been measured in the serum of women after the administration of norgestimate. These studies indicate that 17-deacetyl norgestimate contributes to the pharmacologic response to norgestimate.

Animals↗
PubMed1990

Progestational and androgenic receptor binding affinities and in vivo activities of norgestimate and other progestins.

The progestational and androgenic in vitro receptor binding affinity and the in vivo activity of norgestimate was compared with that of its metabolites and other progestins. The relative binding affinities (RBAs) of norgestimate and its 17-deacetylated metabolite for rabbit uterine progestin receptors were similar to that of progesterone (P); those of 3-keto norgestimate and levonorgestrel were about five times that of P; those of gestodene and 3-keto desogestrel were about nine times that of P. The RBAs of norgestimate, P, and 3-keto norgestimate for rat prostatic androgen receptors were from 0.003 to 0.025 times that of dihydrotestosterone (DHT); those of 3-keto desogestrel, gestodene, and levonorgestrel were from 0.118 to 0.220 times that of DHT. The order of receptor level selectivity represented by the ratio of androgen:progestin IC50 values (with a greater ratio value reflecting a better selectivity) was norgestimate greater than P = 3-keto norgestimate greater than 17-deacetylated norgestimate greater than 3-keto desogestrel greater than gestodene greater than levonorgestrel. In vivo studies demonstrated similar profiles for norgestimate and its 17-deacetylated metabolite. These latter two steroids were equally potent as progestins in stimulating rabbit endometrium, and compared with the other progestins, both steroids exhibited minimal androgenicity as measured by the stimulation of rat prostate growth. In conclusion, these studies, as well as previous preclinical and clinical studies, provide evidence of the selectivity of norgestimate based on minimal androgenicity, indicating an improvement over other progestins used in oral contraceptives.

Animals↗
PubMed1992

Preclinical evaluation of norgestimate, a progestin with minimal androgenic activity.

Norgestimate is a novel progestin with highly selective progestational activity and minimal androgenicity. In rabbits, norgestimate binds to uterine progestin receptors, stimulates the endometrium, and inhibits ovulation. Norgestimate acts directly on target organs, stimulating rabbit endometrium when injected into the uterine cavity and inhibiting luteinizing hormone-releasing hormone-stimulated luteinizing hormone release in dispersed rat pituitary cells in culture. Norgestimate has no estrogenic activity, and like other progestins, it suppresses the action of estrogen. Unlike some other progestins, it is relatively free of androgenic activity. Norgestimate and its 17-deacetylated metabolite demonstrate very poor affinity for androgen receptors compared with levonorgestrel and gestodene and do not exhibit androgenic activity when measured as the stimulation of prostatic growth in immature rats. Norgestimate's lack of affinity for human sex hormone-binding globulin is further evidence of its minimal androgenicity.

Androgens↗
PubMed1989

Norgestimate increases pituitary and hypothalamic concentrations of immunoreactive beta-endorphin.

Progesterone is a potent hormone acting on the female reproductive tract and influencing a series of other functions. Recent studies revealed a correlation between progesterone and brain neurotransmitters and neuropeptides. Our study evaluated the possible effect of norgestimate, a new progestin, on hypothalamic and pituitary beta-endorphin (B-EP) concentration in castrated female rats. Ovariectomy was performed under ethyl ether anesthesia. Treatment was started 3 weeks after surgery. Norgestimate, estradiol benzoate or norgestimate plus estradiol benzoate were administered. The two steroids were dissolved in sesame oil and injected (s.c.) every day for 2 weeks. Pituitary and hypothalamus B-EP concentrations were measured by radioimmunoassay. Our studies showed that norgestimate increases the pituitary and hypothalamic B-EP concentration in female rats, reaching values higher than controls and estrogen-treated rats. Because B-EP has an important role in reproductive function, both modulating gonadotropin secretion and sexual behavior, the present results lead to the hypothesis that norgestimate affecting B-EP concentrations may influence central functions.

Animals↗
PubMed1992

A comparison study of lipid and androgen metabolism with triphasic oral contraceptive formulations containing norgestimate or levonorgestrel.

The effects of norgestimate triphasic (Ortho Tri-Cyclen, Tri-Ciles) and levonorgestrel triphasic (Triphasi) formulations on lipid and androgen metabolism were assessed in a study of 66 healthy women treated through six menstrual cycles. Levels of the following were measured: cholesterol and its subfractions, triglycerides, carrier lipoproteins, estradiol, testosterone, and sex hormone binding globulin (SHBG). Comparison of baseline values with values after 3 and 6 months of treatment indicated that both regimens influenced lipid and androgen metabolism. There was a statistically significant between-regimen difference in levels of high-density lipoprotein, which were favorably increased with norgestimate triphasic but reduced with levonorgestrel triphasic. Related data on SHBG showed that plasma levels of this marker of estrogen/androgen balance were increased significantly more in the norgestimate triphasic group, providing additional evidence of low androgenicity. Both regimens inhibited follicular growth to the same extent, as evidenced by low mean levels of estradiol in all on-therapy cycles; and both decreased free testosterone. Side effects in both groups were minor and characteristic of those observed with low-dose oral contraceptive agents. The results of the study support the reported safety and positive effects of norgestimate on lipid and androgen metabolism, in comparison with a levonorgestrel-containing combined oral contraceptive.

Adolescent↗
PubMed1978

Disposition of norgestimate in the presence and absence of ethinyl estradiol after oral administration to humans.

The disposition of radioactivity following oral administration of 14C-norgestimate was compared to that following administration of the drug in combination with 3H-ethinyl estradiol in humans. Seven normal, healthy female subjects were each administered one capsule orally containing 14C-norgestimate either alone (74.4 muCi, 0.50 mg) or in combination (73.5 muCi, 0.49 mg) with 3H-ethinyl estradiol (103 muCi, 0.14 mg) in polyethylene glycol 400. Peak levels of radioactivity due to carbon-14 and tritium in plasma occurred within 2 hr after drug administration, followed by distribution and elimination phases. The mean apparent elimination half-life and mean cumulative elimination of radioactivity in the urine and feces following 14C-norgestimate administration were not significantly different than those following administration of the combination dose. Approximately 50% of the administered radioactivity due to carbon-14 was excreted in the urine following administration of 14C-norgestimate both in the presence and absence of coadministered 3H-ethinyl estradiol.

Administration, Oral↗
PubMed1992

Norgestimate: a clinical overview of a new progestin.

The efficacy and safety of a new monophasic oral contraceptive, norgestimate/ethinyl estradiol, containing the third-generation progestin, norgestimate (250 micrograms), and ethinyl estradiol (35 micrograms), are reviewed. Norgestimate/ethinyl estradiol demonstrates excellent contraceptive efficacy, with a Pearl index of 0.25. Cycle control is reliable, with a low incidence of breakthrough bleeding and spotting. Because of the minimal androgenicity of norgestimate, norgestimate/ethinyl estradiol has a low impact on carbohydrate and lipid metabolism. It neither reduces the vasodilatory and antiaggregatory prostacyclin nor increases its endogenous antagonist, thromboxane. Norgestimate/ethinyl estradiol has no significant effect on blood coagulation factors. All these characteristics suggest that norgestimate/ethinyl estradiol may be associated with a lower risk of cardiovascular disease than other oral contraceptives currently available. Epidemiologic data, however, are not available, and physicians should be reluctant to prescribe it or any oral contraceptive to patients who have a history of vascular or thrombotic disorders.

Female↗
PubMed1990

Relative binding affinity of norgestimate and other progestins for human sex hormone-binding globulin.

The relative binding affinity of norgestimate for human sex hormone-binding globulin was compared with that of its metabolites and other progestins by measuring their abilities to displace [3H]testosterone from this carrier protein in vitro. Norgestimate and its 17-deacetylated and 3-keto metabolites did not significantly displace [3H]testosterone from sex hormone-binding globulin at concentrations up to 10,000 nM, whereas gestodene, levonorgestrel, and 3-keto desogestrel displaced [3H]testosterone from sex hormone-binding globulin with IC50 concentrations of 23.1, 53.4, and 91.0 nM, respectively. Since it is believed that a progestin may exert androgenic effects by displacing testosterone from sex hormone-binding globulin, thereby increasing circulating levels of free, active testosterone, these data are consistent with the results of preclinical and clinical studies demonstrating the selective progestational activity of norgestimate.

Binding, Competitive↗
PubMed1979

Optimum dosage of an oral contraceptive. A report from the study of seven combinations of norgestimate and ethinyl estradiol.

A statistically designed study was carried out to determine an optimum combination of norgestimate and ethinyl estradiol as an oral contraceptive, based on efficacy, safety, and side-effect patterns. A total of 1,991 patients were studied for more than two years while they were receiving various dosage combinations of these steroids. There were seven dosage combinations studied as part of a statistically orthogonal experimental design, augmented by three combinations near the center. The data arising from these studies were used to fit approximate functions relating the amount of norgestimate and ethinyl estradiol to the rate of spotting and breakthrough bleeding, gastrointestinal disturbance, and pregnancies. These functions, in turn, helped to identify an optimum dosage (0.125 mg. of norgestimate plus 0.035 mg. of ethinyl estradiol) in the entire range of combinations studied.

Adolescent↗
PubMed1990

Efficacy and clinical profile of a new oral contraceptive containing norgestimate. U.S. clinical trials.

The search for a highly selective progestin that exerts a potent and targeted progestational response with minimal or absent androgenic effect has paralleled investigation into the possible impact of these agents on cardiovascular disease in women. Such a progestin, norgestimate (NGM), in a dose of 250 micrograms, has been combined with ethinyl estradiol (EE) 35 micrograms in a new oral contraceptive (OC), Ortho-Cyclen or Cilest. Results of two long-term, multicentric clinical trials demonstrate that this formulation is comparable in efficacy to the norgestrel-containing OC Lo/Ovral. There were no statistically significant differences in pregnancy rate, and both OCs were well-tolerated in a large and diverse study population. In several areas, however, the inherently lower androgenicity of the norgestimate OC produced clinical changes compared with the norgestrel formulation. These changes were primarily evident in the more natural menstrual patterns with the norgestimate OC, its less severe impact on the endometrium, and, most important, its positive impact on lipoprotein metabolism. NGM/EE consistently produced statistically significant increases in high density lipoprotein (HDL) and concomitant improvement in the ratio of low density lipoprotein (LDL) to HDL. By cycle 24, this highly predictive parameter of atherosclerotic risk had decreased 7.7% in the NGM/EE group. Conversely, the norgestrel-containing formulation resulted in statistically significant decreases in HDL and increases in the LDL/HDL ratio; by cycle 24, these patients showed an 18.5% increase in the LDL/HDL ratio. All between regimen comparisons of mean changes in the LDL/HDL ratio were statistically significant, from baseline through cycles 3, 6, 12 and 24.

Adolescent↗
PubMed1990

Supportive European data on a new oral contraceptive containing norgestimate.

Several European studies have been conducted to confirm the efficacy, tolerability, and safety of a new oral contraceptive (OC) combining 250 micrograms norgestimate with 35 micrograms ethinyl estradiol (Ortho-Cyclen or Cilest). In a 12-month multicenter German study of 147 women, treatment with this formulation resulted in no pregnancies, a low incidence of side effects, and excellent cycle control. The drug had no effect on estrogen-mediated fibrin formation nor on the activity of coagulation inhibiting or promoting factors. Similarly, the documented low androgenicity of the highly selective progestational agent norgestimate results in a more positive metabolic profile. Glucose, insulin, and hemoglobin A1c concentrations measured before and after glucose loading were not adversely affected by treatment with the norgestimate-containing OC, and all changes were reversible on its discontinuation. In addition, lipid metabolism was positively influenced by the drug. Low-density lipoprotein cholesterol, a known risk factor for cardiovascular disease, was reduced while the cardioprotective lipid fraction, high-density lipoprotein cholesterol, was increased. Clinical trials to determine the OC's effects on coagulation, endocrine function, and carbohydrate and lipid metabolism are reviewed. Also discussed are several studies demonstrating the formulation's unique endometrial effects, which may possibly be related to its low androgenic activity and consequent low incidence of breakthrough bleeding and amenorrhea.

Adolescent↗
PubMed1992

The new era in oral contraception: pills containing gestodene, norgestimate, and desogestrel.

The latest advance in the 30-year evolution of oral contraceptives (OCs) is the development of three new progestogens: desogestrel, norgestimate, and gestodene. These three new agents are derivatives of levonorgestrel, a gonane hormone, and have been used to develop pills that provide effective pregnancy prevention at lower doses than oral contraceptives using the older steroids. Desogestrel is a prohormone that must first be metabolized into its biologically active form. Norgestimate is already active, but it will be metabolized in part to levonorgestrel. Gestodene is biologically active in its native form. Among the improvements in metabolic parameters seen with this new generation of progestogens are a lack of impact on blood pressure, a balanced effect on coagulation, and a reduced impact on carbohydrate metabolism compared with earlier, higher-dose formulations. The new pills also seem to produce no negative effects on lipid and lipoprotein biosynthesis, and perhaps even improve the ratio of low-density lipoprotein to high-density lipoprotein. Cycle control with all three progestogens is improved, with much lower incidence of intermenstrual bleeding (IMB). Efficacy is as good as with other OCs. Another benefit of the new low-dose progestogens, however, is the low incidence of minor side effects observed in women using these contraceptives. Low incidences of weight gain, headache, and nausea were reported, and the dropout rate because of side effects was low in both international and US trials. Serious side effects are rarely seen with pills containing the new progestogens.(ABSTRACT TRUNCATED AT 250 WORDS)

Contraceptives, Oral, Combined↗
PubMed1989

Clinical aspects of three new progestogens: desogestrel, gestodene, and norgestimate.

Three new 19-nortestosterone progestogens, which are chemically related to levonorgestrel, are now clinically available in combination oral contraceptives in Europe. Desogestrel and norgestimate must be transformed to metabolites for all or part of their biologic activity; gestodene is active in its original form. Compared with present low-dose monophasic and triphasic levonorgestrel formulations, the new combinations appear to be equivalent in efficacy and type and frequency of side effects. Cycle control may be slightly improved with the gestodene preparation and somewhat poorer with the desogestrel regimen. As with the present triphasics, most changes reported in coagulation indexes for the new combinations remained within normal limits, as did changes in carbohydrate and lipid metabolism. There is no present evidence that either the norgestimate or aesogestrel formulation provides a clinical improvement over the levonorgestrel triphasic. In the gestodene combination, the progestogen's increased biologic activity allows further reduction of total steroid dose.

Carbohydrate Metabolism↗
PubMed1992

Lipid and carbohydrate effects of a new triphasic oral contraceptive containing norgestimate.

Data are reported from the combined results of two studies assessing the lipid and carbohydrate effects of a triphasic preparation of norgestimate and ethinyl estradiol (Ortho TriCyclen, Tri-Cilest) over a 2-year period in 1,783 healthy women. Mean values for serum levels of high-density lipoprotein cholesterol (HDL-C) were increased significantly, with a percent change at 24 months of 13.2. Values for the ratio of low-density lipoprotein cholesterol to HDL-C were reduced throughout the study period (mean change of -6.4% at cycle 24). There were no clinically significant changes in fasting blood glucose levels or insulin levels or in values for glycosylated hemoglobin. These results are consistent with those of previous studies and indicate that the triphasic preparation of norgestimate and etinyl estradiol is a selective and minimally androgenic oral contraceptive agent. Long-term therapeutic benefit may accrue from the favorable influences on the lipid profile.

Adolescent↗
PubMed1991

[Acceptance and subjective well-being with a norgestimate combination pill].

683 women were assessed in the present study. All study participants were subjected to an overall clinical examination before and after a 4-month regimen of a low-dose norgestimate-containing combination oral contraceptive (Cileste); in addition, their subjective well-being was investigated by an appropriate questionnaire. 63.3% of the study participants rated drug tolerance as 'very good' and 23.0% rated it as 'good' at evaluation in the 4th cycle. Between the first and second evaluation, we observed a significant improvement of the depressive mood and of skin and hair problems. Women with skin and hair problems often suffer from 'severe dysmenorrhea'. This difference was statistically significant only at the first evaluation (i.e. before the combined norgestimate regimen) and was not observed in the 4th cycle (i.e. during the Cileste regimen), while the incidence of menstrual disturbances was generally found to decrease.

Adolescent↗
PubMed1990

[Clinical evidence of the minimal androgenic activity of norgestimate].

The aim for improving the progestogen component of oral contraceptives is both to increase their selectivity by obtaining a highly effective contraceptive action and to decrease the side effects related to the existing progestogens. The androgenic activity of the existing progestogens modifies the lipid metabolism, particularly a decrease in the high density lipoprotein (HDL) level, which increases the risks of cardiovascular diseases. Thus, the discovery of a progestogen with good anti-ovulatory and minimal androgenic properties would constitute an important progress in the field of oral contraception. Norgestimate (NGM) is a new progestogen presenting an exceptional profile of biological activity, and has proved to be extremely selective, as observed during the clinical trials. The studies described below have been carried out in order to confirm clinically the low androgenic activity of NGM. In two clinical trials, Norgestimate (0.25 mg) associated with 0.035 mg of ethinyloestradiol (NGM 0.25/35) was compared to norgestrel (0.30 mg) associated with 0.030 mg of ethinyloestradiol (Lo/Ovral). In the first trial (1,261 women), the following observations were made: an important increase in the HDL level compared to the base levels in the subjects taking NGM 0.25/35, and an important decrease in the HDL level in those taking Lo/Ovral. The low density lipoprotein (LDL) level increased slightly in the NGM 0.25/35 group, while a higher increase was observed in the Lo/Ovral group. Moreover, the LDL/HDL ratio translates a more favourable lipid profile in the NGM 0.25/35 group, since the values are lower than those observed for the Lo/Ovral group.(ABSTRACT TRUNCATED AT 250 WORDS)

Acne Vulgaris↗
PubMedDate not supplied

Clinical evidence of the minimal androgenic activity of norgestimate.

The goal in improving the progestational component of oral contraceptives (OCs) is to enhance the selectivity of the progestin by achieving a high degree of contraceptive efficacy while decreasing undesirable side effects associated with existing progestational agents. The androgenic activity of current progestins results in changes in lipid metabolism, particularly decreased levels of high-density lipoprotein cholesterol (HDL), which have been associated with an increased risk of coronary heart disease (CHD). A progestin with high antiovulatory activity and minimal androgenicity would offer a clear therapeutic advantage in oral contraception. Norgestimate (NGM) is a new progestin with a unique profile of biological activity that has demonstrated a high level of selectivity in preclinical assays. The present studies were conducted to confirm clinically the low androgenic activity of NGM. Norgestimate (0.25 mg) in combination with 0.035 mg ethinyl estradiol (NGM 0.25/35) was compared with 0.30 mg norgestrel combined with 0.030 mg ethinyl estradiol (Lo/Ovral) in two multicenter clinical studies. In the first study (1,261 women), HDL levels were significantly increased from baseline levels in NGM 0.25/35 subjects but were significantly decreased in Lo/Ovral subjects. Increases in low-density lipoprotein cholesterol (LDL) levels were moderate in the NGM 0.25/35 group and pronounced in the Lo/Ovral group. A favorable lipid profile in NGM 0.25/35 subjects was also reflected in the LDL/HDL ratios, which were significantly lower in the NGM 0.25/35 subjects than in the Lo/Ovral subjects. Sex hormone binding globulin (SHBG) binds androgens, preventing clinical expression of androgenic activity. As a result, elevations in SHBG levels reduce bioactive (unbound) androgen levels and decrease the potential for androgenic side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Acne Vulgaris↗