Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Clin Pharmacol Ther ; 109(3): 728-738, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32996592

RESUMEN

Oral breast cancer prevention medications entail systemic exposure, limiting acceptance by high-risk women. Delivery through the breast skin, although an attractive alternative, requires demonstration of drug distribution throughout the breast. We conducted a randomized double-blind, placebo-controlled phase II clinical trial comparing telapristone acetate, a progesterone receptor antagonist, administered orally (12 mg/day) or transdermally (12 mg/breast) for 4 ± 1 weeks to women planning mastectomy. Plasma and tissue concentrations, measured at five locations in the mastectomy specimen using liquid chromatography tandem mass spectrometry were compared. In 60 evaluable subjects, median drug concentration (ng/g tissue) was 103 (interquartile range (IQR): 46.3-336) in the oral vs. 2.82 (IQR: 1.4-5.5) in the transdermal group. Despite poor dermal permeation, within-breast drug distribution pattern was identical in both groups (R2  = 0.88, P = 0.006), demonstrating that transdermally and orally delivered drug is distributed similarly through the breast, and is strongly influenced by tissue adiposity (P < 0.0001). Other skin-penetrant drugs should be tested for breast cancer prevention.


Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias de la Mama/tratamiento farmacológico , Terapia Neoadyuvante , Norpregnadienos/administración & dosificación , Absorción Cutánea , Adiposidad , Administración Cutánea , Administración Oral , Adulto , Antineoplásicos/efectos adversos , Antineoplásicos/sangre , Neoplasias de la Mama/sangre , Neoplasias de la Mama/cirugía , Quimioterapia Adyuvante , Cromatografía Liquida , Método Doble Ciego , Monitoreo de Drogas , Femenino , Humanos , Mastectomía , Persona de Mediana Edad , Norpregnadienos/efectos adversos , Norpregnadienos/sangre , Espectrometría de Masas en Tándem , Factores de Tiempo , Distribución Tisular , Resultado del Tratamiento , Estados Unidos
2.
Biomed Chromatogr ; 34(10): e4908, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32460397

RESUMEN

In this study, a simplified, sensitive and reliable LC-tandem mass spectrometry method was established and validated for the quantification of ulipristal acetate (UPA) in human plasma and for the investigation of pharmacokinetic profile of UPA following a single oral administration of ella (UPA 30-mg tablet) in healthy Chinese volunteers. Plasma samples were analyzed after being processed by protein precipitation with methanol. Chromatographic separation was performed on a Kinetex EVO C18 column (2.1 × 50 mm, 2.6 µm) using gradient elution with a mobile phase composed of methanol and water containing 2 mm ammonium acetate and 0.3% formic acid at a flow rate of 0.3 mL/min. The chromatographic running time was 4.0 min per sample. The MS detection was performed via an LC system with the positive ion electrospray ionization interface in multiple reaction monitoring mode using the transition of m/z 476.2 → 134.1 for UPA and m/z 479.3 → 416.2 for UPA-d3 [internal standard (IS)], respectively. UPA and IS were monitored without severe interference from the biological matrices. The method was linear over the wide concentration range of 0.300-300 ng/mL. The intra- and inter-day precision and accuracy were well within the limits required for bioanalytical assays. The method was first used to describe the pharmacokinetic characteristic of UPA after a single oral administration of ella in healthy Chinese volunteers. Based on a between-study comparison, there were statistically significant differences (p < .05) between Chinese and Caucasian volunteers for the systemic exposure of UPA, suggesting that race seems to significantly impact the systemic exposure of UPA.


Asunto(s)
Cromatografía Liquida/métodos , Norpregnadienos/sangre , Norpregnadienos/farmacocinética , Espectrometría de Masas en Tándem/métodos , Administración Oral , Adolescente , Adulto , China , Femenino , Humanos , Modelos Lineales , Norpregnadienos/administración & dosificación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
3.
Biomed Chromatogr ; 32(2)2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28869284

RESUMEN

A highly sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry method is described for the simultaneous determination of nomegestrol acetate (NOMAC), a highly selective progestogen, and estradiol (E2), a natural estrogen in human plasma. NOMAC was obtained from plasma by solid-phase extraction, while E2 was first separated by liquid-liquid extraction with methyl tert-butyl ether followed by derivatization with dansyl chloride. Deuterated internal standards, NOMAC-d5 and E2-d4 were used for better control of extraction conditions and ionization efficiency. The assay recovery of the analytes was within 90-99%. The analytes were separated on UPLC BEH C18 (50 × 2.1 mm, 1.7 µm) column using a mobile phase comprising of acetonitrile and 3.0 mm ammonium trifluoroacetate in water (80:20, v/v) with a resolution factor (Rs ) of 3.21. The calibration curves were linear from 0.01 to 10.0 ng/mL for NOMAC and from 1.00 to 1000 pg/mL for E2, respectively. The intra- and inter-batch precision was ≤5.8% and the accuracy of quality control samples ranged from 96.7 to 103.4% for both analytes. The practical applicability of the method is demonstrated by analyzing samples from 18 healthy postmenopausal women after oral administration of 2.5 mg nomegestrol acetate and 1.5 mg estradiol film-coated tablets under fasting.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Estradiol/sangre , Megestrol/sangre , Norpregnadienos/sangre , Posmenopausia/metabolismo , Espectrometría de Masas en Tándem/métodos , Adulto , Anciano , Compuestos de Dansilo , Estradiol/administración & dosificación , Estradiol/farmacocinética , Femenino , Humanos , Modelos Lineales , Megestrol/administración & dosificación , Megestrol/farmacocinética , Persona de Mediana Edad , Norpregnadienos/administración & dosificación , Norpregnadienos/farmacocinética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
4.
Artículo en Inglés | MEDLINE | ID: mdl-28570936

RESUMEN

The progesterone receptor modulator, Ulipristal acetate (UPA) has proven to be an effective emergency contraceptive. Conflicting data has been reported that suggests different efficacy of the drug in different populations, which may be explained by the systemic exposure to the drug. A UPLC-MS/MS method was developed and validated for the accurate and sensitive measurement of UPA in human serum to address this matter. UPA was extracted from human serum using liquid-liquid extraction with a combination of hexane and dichloromethane. An analytical platform comprising reverse-phase chromatographic separation followed by mass spectrometric detection by positive electrospray ionization in multiple reaction monitoring was used for quantitation of UPA within 7min. The method was linear from 0.1 to 250ng/mL. The matrix effect was minimal and intra- and inter-assay precision and accuracy were all within the acceptable limits. UPA was found to be stable at all processing and storage conditions. The method was used to investigate the pharmacokinetics of UPA in a clinical trial designed to explore the effect of obesity on its bioavailability.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Norpregnadienos/sangre , Espectrometría de Masas en Tándem/métodos , Calibración , Estabilidad de Medicamentos , Humanos , Reproducibilidad de los Resultados
5.
Gynecol Endocrinol ; 33(3): 218-222, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27908210

RESUMEN

Evidence on the effects of hormonal contraceptives on female sexuality is conflicting. We enrolled 556 women, divided into six groups: two composed of subjects using a combined hormonal contraceptive (COC) containing 0.020 ("COC20") and 0.030 ("COC30") mg of ethynyl estradiol (EE), "natural", using COC containing 1.5 mg of estradiol (E2), "ring", using a vaginal ring releasing each day 0.015 mg of EE + 0.120 of etonogestrel, "subcutaneous", using a progestin only subcutaneous contraceptive implant releasing etonogestrel and "controls", using no hormonal contraceptive methods. The subjects were required to answer to the McCoy female sexuality questionnaire and were subjected to a blood test for hormonal evaluation. An ultrasound evaluation of the dorsal clitoral artery was also performed. The higher McCoy sexological value were recorded in the subdermal group; significant differences were recorded among the groups in terms of hormone distribution, with the higher levels of androstenedione in subdermal and control groups. The ultrasound evaluation of dorsal clitoral artery shows a significative correlation between pulsatility and resistance indices and orgasm parameters of McCoy questionnaire. The recorded difference in the sexual and hormonal parameters among the studied hormonal contraceptives may guide toward the personalization of contraceptive choice.


Asunto(s)
Anticonceptivos Femeninos/administración & dosificación , Dispositivos Anticonceptivos Femeninos , Anticonceptivos Orales Combinados/administración & dosificación , Anticonceptivos Hormonales Orales/administración & dosificación , Estrógenos/administración & dosificación , Progestinas/administración & dosificación , Conducta Sexual/efectos de los fármacos , Adulto , Clítoris/irrigación sanguínea , Clítoris/diagnóstico por imagen , Clítoris/efectos de los fármacos , Anticonceptivos Femeninos/efectos adversos , Anticonceptivos Femeninos/sangre , Anticonceptivos Femeninos/farmacocinética , Dispositivos Anticonceptivos Femeninos/efectos adversos , Anticonceptivos Orales Combinados/efectos adversos , Anticonceptivos Orales Combinados/sangre , Anticonceptivos Orales Combinados/farmacocinética , Anticonceptivos Hormonales Orales/efectos adversos , Anticonceptivos Hormonales Orales/sangre , Anticonceptivos Hormonales Orales/farmacocinética , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/efectos adversos , Desogestrel/administración & dosificación , Desogestrel/efectos adversos , Desogestrel/sangre , Desogestrel/farmacocinética , Relación Dosis-Respuesta a Droga , Implantes de Medicamentos , Estrógenos/efectos adversos , Estrógenos/sangre , Estrógenos/farmacocinética , Femenino , Humanos , Italia , Megestrol/administración & dosificación , Megestrol/efectos adversos , Megestrol/sangre , Megestrol/farmacocinética , Norpregnadienos/administración & dosificación , Norpregnadienos/efectos adversos , Norpregnadienos/sangre , Norpregnadienos/farmacocinética , Orgasmo/efectos de los fármacos , Progestinas/efectos adversos , Progestinas/sangre , Progestinas/farmacocinética , Flujo Sanguíneo Regional/efectos de los fármacos , Autoinforme , Ultrasonografía Doppler , Adulto Joven
6.
Contraception ; 93(2): 133-8, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26365792

RESUMEN

OBJECTIVE: Nomegestrol acetate (NOMAC), a selective progestogen, and 17ß-estradiol (E2), which is identical to endogenous oestrogen, are components of a new monophasic combined oral contraceptive--NOMAC/E2. This study aimed to compare pharmacokinetics (PK) of NOMAC in adolescent and adult women following a single dose of NOMAC/E2. STUDY DESIGN: Healthy postmenarcheal adolescent (14-17years) and adult (18-50years) women received a single dose of NOMAC/E2 (2.5mg/1.5mg) in this single-centre, open-label, parallel-group Phase 1 study (EudraCT# 2008-002142-38). Blood samples were obtained for PK analysis, and concentrations of NOMAC, E2 and its metabolite estrone (E1) were determined for up to 129h following dosing to obtain PK data. An independent whole-body physiology-based pharmacokinetic (WB-PBPK) simulation model of NOMAC based on an independent Phase 3 dataset was used to scale NOMAC concentration-time plots to adolescents. RESULTS: Overall, 52 women were screened, of whom 30 (15 adolescents and 15 adults) were enrolled. No statistically significant differences were observed between the adolescent and adult groups for the clinically evaluated NOMAC PK parameters [maximum concentration (Cmax), area under the curve (AUC) and half-life (t1/2)]. The PK of E2 and E1 showed extensive overlap between both age groups. The WB-PBPK model accurately predicted NOMAC AUC and Cmax values in both groups. CONCLUSIONS: No differences were observed in the clinically evaluated PK parameters for NOMAC between adolescent and adult women after a single dose of NOMAC/E2. The WB-PBPK model accurately predicted NOMAC PK data (EudraCT# 2008-002142-38). IMPLICATIONS: PK studies in adolescents are challenging because of ethical considerations. The whole-body physiology-based model described here complements classic noncompartmental and population PK approaches. The utility of this method is its ability to expand to adolescent postmenarcheal girls by using virtual postmenarcheal adolescent population data and applying physiological scaling.


Asunto(s)
Factores de Edad , Anticonceptivos Orales Combinados/administración & dosificación , Estradiol/administración & dosificación , Megestrol/farmacocinética , Modelos Biológicos , Norpregnadienos/farmacocinética , Congéneres de la Progesterona/farmacocinética , Adolescente , Adulto , Estradiol/sangre , Estradiol/farmacocinética , Estrona/sangre , Femenino , Semivida , Humanos , Megestrol/administración & dosificación , Megestrol/sangre , Persona de Mediana Edad , Norpregnadienos/administración & dosificación , Norpregnadienos/sangre , Adulto Joven
7.
Contraception ; 90(6): 565-74, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25193534

RESUMEN

OBJECTIVE: To determine whether a 3-month contraceptive vaginal ring (CVR) delivering ulipristal acetate (UPA) can inhibit ovulation in 90% of cycles. STUDY DESIGN: This was a randomized dose-finding parallel group clinical trial. Fifty-five healthy women with normal ovulation at baseline were randomized to receive a low-dose (1500 µg/day) or a high-dose (2500 µg/day) UPA-CVR for two consecutive 12-week treatment periods, followed by a recovery cycle. A subgroup of women received levonorgestrel (LNG) 1.5 mg orally twice (at the end of both 12-week ring periods) or once (at the end of the 24-week treatment). The primary outcome was ovulation suppression assessed by transvaginal ultrasound and hormone levels. Secondary outcomes included endometrial safety and bleeding patterns. RESULTS: All subjects showed normal ovulation at baseline and recovery. Ovulation suppression was seen in 81.8% (95% CI: 73.3%, 88.5%) and 86.1% (95% CI: 78.1%, 92%) of treatment cycles with low and high-dose, respectively. Benign progesterone receptor modulator associated endometrial changes (PAEC) were seen during treatment; 78.8% at week 24, but resolved at recovery cycle. A few cases of heavy bleeding occurred near the end of the 24-week treatment, but a single dose of LNG every 12 weeks reduced the increase in endometrial thickness during the second treatment period and prevented excessive bleeding. CONCLUSION: The 3-month UPA-CVR may become an effective long-acting, user-controlled estrogen-free contraceptive. The greatest suppression of ovulation was seen with the 2500-µg/day ring. IMPLICATIONS: The 3-month CVR delivering UPA 2500 µg/day can become an effective user-controlled estrogen-free contraceptive method. Benign PAEC during treatment returns to normal after discontinuation. The prevention of occasional excessive withdrawal bleeding, either by a progestin or by using higher UPA levels to increase follicle suppression may permit prolonged treatment.


Asunto(s)
Anticoncepción/métodos , Anticonceptivos Femeninos/administración & dosificación , Dispositivos Anticonceptivos Femeninos , Norpregnadienos/administración & dosificación , Adulto , Anticonceptivos Femeninos/efectos adversos , Anticonceptivos Femeninos/sangre , Anticonceptivos Femeninos/farmacología , Endometrio/efectos de los fármacos , Femenino , Humanos , Norpregnadienos/efectos adversos , Norpregnadienos/sangre , Norpregnadienos/farmacología , Folículo Ovárico/efectos de los fármacos , Pruebas de Función Ovárica , Ovario/efectos de los fármacos , Ovulación/efectos de los fármacos , Inhibición de la Ovulación/efectos de los fármacos , Receptores de Progesterona/administración & dosificación , Receptores de Progesterona/efectos de los fármacos , Hemorragia Uterina/tratamiento farmacológico , Vagina/efectos de los fármacos , Adulto Joven
8.
Contraception ; 87(2): 193-200, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22898360

RESUMEN

BACKGROUND: The pharmacokinetics of the monophasic oral contraceptive nomegestrol acetate (NOMAC) plus 17ß-estradiol (E(2)) were investigated after a single dose and multiple dosing. STUDY DESIGN: NOMAC/E2 (2.5 mg/1.5 mg) was administered daily to healthy women (18-50 years, n=23) for 24 days; blood samples for pharmacokinetic analysis were obtained on Day 24 and again, after a 10-day pill-free interval, on Day 35 after a single dose. RESULTS: NOMAC reached steady state after 5 days with mean ±standard deviation (SD) trough NOMAC concentration (C(av)) of 4.4±1.4 ng/mL. On Day 24, mean±SD peak NOMAC concentration (Cmax, 12.3±3.5 ng/mL) was reached in mean 1.5 h (t(max)); the mean±SD elimination half-life (t(½)) was 45.9±15.3 h. After a single dose, NOMAC mean±SD C(max) was 7.2±2.0 ng/mL and mean±SD t(½) was 41.9±16.2 h. On Day 24, E2 mean±SD C(av) was 50.3±25.7 pg/mL; mean±SD Cmax was 86.0±51.3 pg/mL. After a single dose, mean±SD E2 Cmax was 253±179 pg/mL. CONCLUSIONS: These data demonstrate that NOMAC/E2 has a pharmacokinetic profile consistent with once-daily dosing.


Asunto(s)
Anticonceptivos Orales Combinados/farmacocinética , Estradiol/administración & dosificación , Estradiol/farmacocinética , Megestrol/administración & dosificación , Megestrol/farmacocinética , Norpregnadienos/administración & dosificación , Norpregnadienos/farmacocinética , Adolescente , Adulto , Disponibilidad Biológica , Anticonceptivos Orales Combinados/administración & dosificación , Anticonceptivos Orales Combinados/efectos adversos , Estradiol/sangre , Estrona/sangre , Femenino , Humanos , Megestrol/sangre , Persona de Mediana Edad , Norpregnadienos/sangre
9.
Int J Clin Pharmacol Ther ; 51(1): 26-33, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23110788

RESUMEN

OBJECTIVE: Ulipristal acetate is a novel selective progesterone receptor modulator for the treatment of benign gynecological conditions such as uterine myoma. As a Biopharmaceutical Classification System (BCS) II compound, it is highly soluble at low pH but has low solubility at neutral conditions. Esomeprazole, a proton pump inhibitor used widely for treatment of gastric and duodenal ulcers, efficiently increases gastric pH. Thus, the aim of this study was to determine the effects of esomeprazole on the pharmacokinetics of ulipristal acetate. MATERIALS AND METHODS: This was a nonrandomized, single sequence, 2 period, open, study in 18 healthy female subjects. Subjects received oral ulipristal acetate tablets (10 mg) once on Days 1 and 13 and daily esomeprazole administrations (20 mg) from Days 9 through 14. RESULTS: Co-administration of esomeprazole decreased geometric mean Cmax of ulipristal acetate by 65% (geometric mean ratio point estimate (90% CI): 0.35 (0.28 - 0.42)), and delayed median tmax from 0.75 to 1.00 h (Hodges-Lehmann estimate of difference (90% CI): tmax 0.63 (0.25 - 1.25)) but had minor effects on AUCs of +15% and +11% (geometric mean ratio point estimates (90% CI): AUC0-t 1.15 (1.02 - 1.31) and AUC0-∞ (1.11 (0.98 - 1.27)), respectively. A total of 6 adverse events were reported by 4 subjects, none of them being serious. CONCLUSIONS: Concomitant use of ulipristal acetate with esomeprazole at therapeutic concentrations led to a modified absorption rate while exposure in terms of AUC remained close to bioequivalence limits. In the context of chronic administration of ulipristal acetate, no clinically significant effects are expected from co-administration with drugs increasing gastric pH.


Asunto(s)
Anticonceptivos/farmacocinética , Esomeprazol/farmacología , Jugo Gástrico/efectos de los fármacos , Norpregnadienos/farmacocinética , Inhibidores de la Bomba de Protones/farmacología , Adolescente , Adulto , Análisis de Varianza , Área Bajo la Curva , Anticonceptivos/efectos adversos , Anticonceptivos/sangre , Diarrea/inducido químicamente , Interacciones Farmacológicas , Esomeprazol/efectos adversos , Esomeprazol/sangre , Femenino , Humanos , Concentración de Iones de Hidrógeno , Persona de Mediana Edad , Norpregnadienos/efectos adversos , Norpregnadienos/sangre , Inhibidores de la Bomba de Protones/efectos adversos , Inhibidores de la Bomba de Protones/sangre , Valores de Referencia , Equivalencia Terapéutica , Adulto Joven
10.
AAPS J ; 13(4): 665-73, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22028249

RESUMEN

Telapristone is a selective progesterone antagonist that is being developed for the long-term treatment of symptoms associated with endometriosis and uterine fibroids. The population pharmacokinetics of telapristone (CDB-4124) and CDB-4453 was investigated using nonlinear mixed-effects modeling. Data from two clinical studies (n = 32) were included in the analysis. A two-compartment (parent) one compartment (metabolite) mixture model (with two populations for apparent clearance) with first-order absorption and elimination adequately described the pharmacokinetics of telapristone and CDB-4453. Telapristone was rapidly absorbed with an absorption rate constant (Ka) of 1.26 h(-1). Moderate renal impairment resulted in a 74% decrease in Ka. The population estimates for oral clearance (CL/F) for the two populations were 11.6 and 3.34 L/h, respectively, with 25% of the subjects being allocated to the high-clearance group. Apparent volume of distribution for the central compartment (V2/F) was 37.4 L, apparent inter-compartmental clearance (Q/F) was 21.9 L/h, and apparent peripheral volume of distribution for the parent (V4/F) was 120 L. The ratio of the fraction of telapristone converted to CDB-4453 to the distribution volume of CDB-4453 (Fmet(est)) was 0.20/L. Apparent volume of distribution of the metabolite compartment (V3/F) was fixed to 1 L and apparent clearance of the metabolite (CLM/F) was 2.43 L/h. A two-compartment parent-metabolite model adequately described the pharmacokinetics of telapristone and CDB-4453. The clearance of telapristone was separated into two populations and could be the result of metabolism via polymorphic CYP3A5.


Asunto(s)
Modelos Biológicos , Norpregnadienos/farmacocinética , Adulto , Área Bajo la Curva , Humanos , Persona de Mediana Edad , Norpregnadienos/sangre
11.
Hum Reprod ; 18(9): 1820-7, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12923133

RESUMEN

BACKGROUND: Progesterone receptor modulators have potential therapeutic use in progesterone-dependent conditions such as endometriosis, fibroids and induction of labour. The synthetic steroid CDB-2914 binds to the progesterone and glucocorticoid receptors. In animals it has antiprogestational activity at doses 50-fold less than those required for antiglucocorticoid effects. METHODS AND RESULTS: We evaluated the biological activity, blood levels and safety of CDB-2914 at escalating single doses, in 36 normally cycling women at mid-luteal phase. CDB-2914 at doses of 1-100 mg did not change luteal phase length, but after 200 mg, all women had early endometrial bleeding. Four women with early menses had concurrent functional luteolysis (one at 10, 50, 100 and 200 mg). There were no biochemical or clinical signs of toxicity, and no effect on urinary cortisol or circulating thyroxine, prolactin, adrenocorticotrophic hormone or renin levels. Higher serum equivalents of CDB-2914 were observed by radioimmunoassay than by high performance liquid chromatography detection, indicating a considerable contribution of metabolites. CONCLUSIONS: Mid-luteal administration of CDB-2914 antagonizes progesterone action on the endometrium, in a dose-dependent fashion, without apparent antiglucocorticoid effects. Further study of CDB-2914 is needed to determine its clinical role.


Asunto(s)
Fase Luteínica , Norpregnadienos/administración & dosificación , Progestinas/antagonistas & inhibidores , Adulto , Cromatografía Líquida de Alta Presión , Cuerpo Lúteo/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Fase Luteínica/efectos de los fármacos , Luteólisis , Ciclo Menstrual/efectos de los fármacos , Menstruación/efectos de los fármacos , Norpregnadienos/sangre , Radioinmunoensayo , Valores de Referencia , Factores de Tiempo
12.
Steroids ; 65(10-11): 621-7, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11108868

RESUMEN

Prevention of coronary artery disease has been recognized as a major benefit of estrogen replacement therapy (ERT) in postmenopausal women. However, endometrial hyperplasia induced by unopposed ERT has raised important safety concerns. Progesterone or synthetic progestins have been used in combined hormone replacement therapy (HRT) to prevent endometrial cancer risk. Therefore, a major concern has been to ensure that the vascular beneficial effects of estrogens are not opposed when combined with progestins. Nomegestrol acetate (NOMAC) is an orally active progestin widely prescribed for HRT. Its vascular effects were evaluated in two models of coronary vascular reactivity in primates: 1) the paradoxical vasoconstriction to acetylcholine (Ach) coronary infusion after 5 months of mildly atherogenic diet in ovariectomized (OVX) Cynomolgus monkeys and 2) the pharmacologically evoked coronary vasospasm in the OVX Rhesus monkey. In the first model, after 3 months of continuous oral administration in the diet at 0.1 mg/kg/day, E2 prevented the paradoxical response to Ach, alone as well as combined with 0.25 mg/kg/day NOMAC, whereas NOMAC counteracted the endometrial stimulation. In the second model, after one artificial cycle consisting of 28 days of E2 subcutaneous (s.c.) implant and of daily oral gavage with 1 mg/kg/day of NOMAC for the last 14 days, no vasospasm (0 of 11 tested animals) occurred when the complete challenge protocol, including serotonin and the thromboxane agonist U46619, was administered to OVX Rhesus monkeys. In the balanced crossover design, identical artificial cycles with medroxyprogesterone acetate (MPA) at the same dose resulted in 7 vasospasms in 12 animals. In parallel, effective progestative activity was demonstrated by a secretory pattern in endometrial sections obtained at the end of the cycle. In these two nonhuman primate cardiovascular models, NOMAC did not have the negating effects observed with MPA.


Asunto(s)
Arterias/efectos de los fármacos , Megestrol , Acetilcolina/administración & dosificación , Acetilcolina/farmacología , Animales , Velocidad del Flujo Sanguíneo/efectos de los fármacos , División Celular/efectos de los fármacos , Enfermedad Coronaria/prevención & control , Vasoespasmo Coronario/inducido químicamente , Endometrio/citología , Endometrio/efectos de los fármacos , Endometrio/metabolismo , Estradiol/administración & dosificación , Estradiol/sangre , Estradiol/farmacología , Femenino , Macaca fascicularis , Macaca mulatta , Acetato de Medroxiprogesterona/administración & dosificación , Acetato de Medroxiprogesterona/farmacología , Modelos Animales , Norpregnadienos/administración & dosificación , Norpregnadienos/sangre , Norpregnadienos/farmacología , Congéneres de la Progesterona/administración & dosificación , Congéneres de la Progesterona/farmacología , Vasoconstricción/efectos de los fármacos
13.
Hum Reprod ; 15(5): 1100-6, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10783360

RESUMEN

The overall aim of these studies was to investigate the oral and i.m. bioavailability of CDB-2914 in intact female rhesus monkeys, and to compare the serum concentrations of CDB-2914 with that of mifepristone following oral administration. In the first study, a 50 mg bolus of CDB-2914 per monkey was administered intravenously, orally or intramuscularly. The area under the serum concentration-time curve for 72 h (AUC(0-72)) following i.v. injection was 18 320 +/- 2718 ng/ml*h, and that for oral administration was 10 464 +/- 3248 ng/ml*h. Thus, the oral bioavailability of CDB-2914 equivalents was 56%. The AUC(0-168 h) following i.m. injection was 11 226 +/- 1130 ng/ml*h. Therefore, the i.m. bioavailability of CDB-2914 equivalents was 62%. In the second study, the serum concentrations of CDB-2914 and mifepristone equivalents were compared following an oral bolus dose in two different formulations. When administered at 5 mg/kg in aqueous suspending vehicle (ASV), the mean peak serum concentration (C(max)) of CDB-2914 equivalents (192 +/- 64 ng/ml) occurred at 5 +/- 1 h, whereas the C(max) of mifepristone equivalents (82 +/- 25 ng/ml) occurred at 3 +/- 1 h. Following administration in gelatin capsules (35 mg/monkey), the C(max) of CDB-2914 equivalents (129 +/- 24 ng/ml) occurred at 5 +/- 1 h, while the C(max) of mifepristone equivalents (31 +/- 8 ng/ml) occurred at 3 +/- 1 h. The serum concentration (AUC(0-120 h)) of CDB-2914 equivalents was 4.7- or 5. 3-fold greater than that of mifepristone equivalents when administered orally in ASV or gelatin capsules respectively. The serum protein binding characteristics of CDB-2914 were also studied. CDB-2914 bound to human alpha(1)-acid glycoprotein (AAG), but not with as high an affinity as mifepristone. In contrast, neither CDB-2914 nor mifepristone bound with high affinity to AAG, corticosteroid binding globulin or sex hormone binding globulin in monkey serum. Collectively, these results indicated that CDB-2914 was more efficiently absorbed than mifepristone following oral administration to female rhesus monkeys.


Asunto(s)
Anticonceptivos Sintéticos Poscoito/administración & dosificación , Anticonceptivos Sintéticos Poscoito/sangre , Mifepristona/administración & dosificación , Mifepristona/sangre , Norpregnadienos/administración & dosificación , Norpregnadienos/sangre , Administración Oral , Animales , Área Bajo la Curva , Disponibilidad Biológica , Anticonceptivos Sintéticos Poscoito/farmacocinética , Formas de Dosificación , Femenino , Humanos , Inyecciones Intramusculares , Inyecciones Intravenosas , Macaca mulatta , Mifepristona/farmacocinética , Norpregnadienos/farmacocinética , Globulina de Unión a Hormona Sexual/metabolismo , Transcortina/metabolismo
14.
J Clin Endocrinol Metab ; 44(5): 983-5, 1977 May.
Artículo en Inglés | MEDLINE | ID: mdl-858781

RESUMEN

R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione), a synthetic progestin, was tested for its binding to purified human transcortin, albumin and human serum. Scatchard analysis showed that R5020 bound relatively weakly to transcortin (Kass = 8 X 10(6)M-1); in 20% human serum or albumin greater than 90% was bound with low Kass and an indeterminate number of binding sites.


Asunto(s)
Norpregnadienos/sangre , Congéneres de la Progesterona/sangre , Albúmina Sérica/metabolismo , Transcortina/metabolismo , Humanos , Cinética , Unión Proteica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...