RESUMEN
PURPOSE OF REVIEW: The aim of this review is to provide an overview of surgical treatment options for male infertility including varicocelectomy, treatment of ejaculatory duct obstruction, vasovasostomy, and sperm extraction, and to review recent advances in techniques and technologies that may improve operative outcomes. RECENT FINDINGS: Microscopic subinguinal varicocelectomy has been shown to have the highest success rates with lowest rates of complications, and may be facilitated by the use of Doppler, indocyanine green angiography, and the 4K3D operating video microscope. The standard treatment for ejaculatory duct obstruction by transurethral resection of the ejaculatory ducts has changed little over time, but vesiculoscopy may allow for temporary dilation of an obstruction to allow for natural conception, while also offering diagnostic capabilities. Use of the robotic platform has gained popularity for vasectomy reversals but controversy remains regarding the cost-effectiveness of this option. Recently, a reinforcing suture technique has been described for vasovasostomy to minimize anastomotic breakdown and reversal failure. Finally, gray-scale and color-enhanced ultrasound may improve ability to predict successful sperm retrieval during extraction procedures. SUMMARY: Though the fundamentals of surgical treatment options for male infertility have changed little with time, technological advancements have contributed to improved surgical outcomes over recent years.
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Infertilidad Masculina , Vasovasostomía , Conductos Eyaculadores/diagnóstico por imagen , Conductos Eyaculadores/cirugía , Humanos , Infertilidad Masculina/etiología , Infertilidad Masculina/cirugía , Masculino , EspermatozoidesRESUMEN
Post-vasectomy pain syndrome (PVPS) is a rare, but devastating outcome following vasectomy. Given the widespread utilization of vasectomy for permanent contraception, with more than 500,000 procedures performed annually in the United States, it can be a significant challenge for both patients and providers. Vasectomy reversal is a surgical option for men who fail conservative or medical management. Despite improvements in technique, vasectomy carries some inherent risks making pre-procedure counseling regarding the risks of PVPS paramount. Chronic post-operative pain, or PVPS, occurs in 1-2% of men undergoing the procedure. This review will examine the utility of vasectomy reversal as a means of addressing PVPS.
RESUMEN
Erectile dysfunction (ED) is a common sexual disorder with numerous etiologies involving multiple organ systems that leads to significant distress and decreased quality of life for the affected men. Fortunately, there are several modalities and interventions for treating ED. Oral medications, intra-urethral compounds, intracorporeal injections, vacuum-assist devices and surgically implanted prostheses are all part of the treatment algorithm. One of the first-lines and certainly the most widely used options for treating ED is the family of oral phosphodiesterase type 5 inhibitors (PDE5I). The introduction of these medications in the late 1990s revolutionized the field of sexual medicine. Currently there are no guidelines and minimal literature to help providers choose among drugs in this class. This review will address differences in efficacy and side effects between various members of the oral selective phosphodiesterase-5 inhibitor class of drugs.
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Persistent Müllerian duct syndrome is a rare genetic disorder characterized by a male with retained Müllerian structures. Remnant excision must be considered due to the possibility of malignant degeneration. We review a case of delayed diagnosis in a 25-year-old man presenting with hematuria. Preoperative counseling must emphasize the risk of malignancy versus the risks to fertility. The da Vinci robot offers a novel, safe approach for excision of the relevant Müllerian structures. Dissection should be limited to structures superior to the cavernosal neurovascular bundles to preserve the continence and erectile function. A semen analysis is recommended preoperatively to determine effects on fertility.
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PURPOSE: Since the early 1980s with the inception of fetal intervention for obstructive uropathy, there have been creative attempts to improve both perinatal and long-term outcomes. Despite advances in technology and an improved understanding of lower urinary tract obstruction (LUTO) in the fetus, the results for these therapeutic interventions remain guarded and the long-term renal morbidity among survivors remains problematic. RECENT FINDINGS: Fetal LUTO represents a range of disorders but the most common of these is posterior urethral valves (PUVs). Selection criteria for candidates of possible intervention have improved with our understanding of fetal renal physiology. Serial urinalysis has marginally improved our ability to predict those that may ultimately respond to treatment [1,2], but the potential in the development of biomarkers for renal development or maldevelopment holds greater promise [3]. Advancements in fetal surgery may result in less fetal and maternal morbidity, but limited long-term improvement in outcomes highlights the controversial nature of the various interventions [4-10]. We must counsel families that fetal surgery offers hope but we cannot allow them to hold unrealistic expectations for cure. SUMMARY: In appropriately selected fetuses, intervention may improve perinatal survival but not without risk to mother and fetus. Long-term renal outcomes remain problematic amongst survivors. In the case of PUV, postnatal primary valve ablation remains the cornerstone of treatment for nephron preservation; however, our ability to mimic these results in the prenatal population remains poor [11]. Disease severity has likely predetermined those that will survive through the perinatal period with or without intervention. Nonetheless, our drive to assess and manage fetal obstructive uropathy perseveres so that we may ultimately relieve obstruction and preserve renal and lung function. We must maintain optimism that continued advances will ultimately improve outcomes, but also be realistic with our current expectations. This paper reviews the status of current in utero interventions and outcomes.
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Enfermedades Fetales/cirugía , Feto/cirugía , Obstrucción Uretral/cirugía , Obstrucción del Cuello de la Vejiga Urinaria/cirugía , Femenino , Humanos , Embarazo , Procedimientos Quirúrgicos Urológicos/métodosRESUMEN
OBJECTIVE: We present our experience with pediatric robotic-assisted laparoscopic partial nephrectomy of a nonfunctioning moiety in a duplicated system (RALPN), comparing techniques and outcomes with those previously reported in the literature. To our knowledge, this is the largest series of this surgical procedure to date. PATIENTS AND METHODS: We retrospectively reviewed all pediatric patients at our institution that had undergone RALPN from 2006 to 2012. RESULTS: Twenty-one patients underwent RALPN between 2006 and 2012. Mean patient age was 4.1 years. Mean operative time was 301 min. Mean estimated blood loss was 36 ml. Mean length of stay was 38 h. The majority of cases were performed with three laparoscopic ports. At initial follow-up ultrasound 6/21 (29%) demonstrated a fluid collection. The majority of these collections occurred in cases where the resection defect was not closed intraoperatively (42% of cases vs. 11% of cases). All fluid collections were asymptomatic and managed conservatively. CONCLUSION: RALPN is associated with low complication rates. The robotic system allows for the use of only two small robotic working ports in most cases. Postoperative fluid collections may be prevented by formal closure of the polar defect, but fluid collections that do occur can be followed conservatively.
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Túbulos Renales Colectores/anomalías , Túbulos Renales Colectores/cirugía , Nefrectomía/métodos , Robótica/métodos , Centros Médicos Académicos , Adolescente , Factores de Edad , Niño , Preescolar , Estudios de Cohortes , District of Columbia , Femenino , Estudios de Seguimiento , Hospitales Pediátricos , Humanos , Lactante , Laparoscopía/instrumentación , Laparoscopía/métodos , Tiempo de Internación , Masculino , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Tempo Operativo , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/fisiopatología , Estudios Retrospectivos , Factores Sexuales , Resultado del Tratamiento , Anomalías Urogenitales/diagnóstico , Anomalías Urogenitales/cirugíaRESUMEN
Indirect assessments have shown a superior lung deposition of HFA-BDP (Ventolair/Qvar) compared to CFC-BDP (Aerobec). The aim of this study was to assess the concentrations of BDP and its metabolite 17-BMP in airways and peripheral tissue from resected lung specimens after inhalation of these BDP formulations. Immediately prior to surgery for lung cancer, 10 patients inhaled 1000 microg of either CFC-BDP (n = 5) or HFA-BDP (n = 5) Mouthwash was collected after inhalation, and serum before, during, and after surgery. There was no significant difference between CFC and HFA in the concentration of 17-BMP in bronchi (median, 4365 vs 4121 pg/g tissue). After CFC, concentrations of 17-BMP were lower in peripheral tissue (1424 vs 2089 pg/g; ANCOVA, p = 0.001) and in serum taken immediately after inhalation (688 vs 1219 pg/ml, p < 0.01). Furthermore, the CFC group showed a higher concentration of BDP in the mouthwash (17,660 vs 1320 ng/ml, p < 0.05), but the concentration of 17-BMP was lower (452 vs 1028 ng/ml, n.s.). These findings indicate a predominantly peripheral deposition of HFA-BDP, in line with previous data. They also provide evidence for a faster uptake and metabolism of HFA-BDP, probably because BDP is dissolved in HFA and has a smaller particle size distribution than the CFC suspensions.
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Propelentes de Aerosoles/química , Beclometasona/análogos & derivados , Beclometasona/metabolismo , Beclometasona/farmacocinética , Clorofluorocarburos/química , Glucocorticoides/farmacología , Hidrocarburos Fluorados/química , Administración por Inhalación , Adulto , Anciano , Beclometasona/administración & dosificación , Beclometasona/análisis , Bronquios/química , Portadores de Fármacos , Femenino , Glucocorticoides/administración & dosificación , Glucocorticoides/análisis , Humanos , Pulmón/química , Masculino , Persona de Mediana Edad , Tamaño de la Partícula , Factores de Tiempo , Distribución TisularRESUMEN
We set out to evaluate lung deposition, systemic availability, and basic pharmacokinetic parameters of beclomethasone dipropionate (BDP) in children with chronic asthma. Plasma levels of BDP, 17 and 21 beclomethasone monopropionate (17-BMP and 21-BMP), and beclomethasone were measured after an intravenous infusion of 60 microg BDP and after inhalation of A) 100 microg HFA-BDP, B) 200 microg HFA-BDP, C) 200 microg HFA-BDP after ingestion of charcoal to block gastrointestinal (GI) absorption of drug, and D) 400 microg CFC-BDP. A breath-actuated pMDI (Autohaler) was used for HFA inhalations, and a pMDI with a large volume spacer (Volumatic) for CFC inhalations. Treatments A-D were given in a randomized, cross-over design. Fourteen patients aged 10-14 years completed all 5 study days. The mean systemic bioavailabilities in percent of dose leaving the canister valve (ex-valve) were 70% (100 HFA), 74% (200 HFA), 60% (200 HFA + charcoal), and 27% (400 microg CFC). After HFA treatment, 82% of the systemically available dose was absorbed through the lungs, and 18% from the gastrointestinal tract. The estimated bioavailability of BDP from the GI tract was 68%. BDP was metabolized to 17-BMP within minutes. Mean steady-state volume of distribution of 17-BMP was 84 L, and the mean terminal half-life (T((1/2))) after the four inhalations was 2.7 hr (range, 2.2-3.7 hr). Mean T((1/2)) and clearance after i.v. administration were 1.7 hr and 0.9 L/min, respectively. The HFA Autohaler delivers approximately three times as much BDP to the intrapulmonary airways as a CFC-pMDI with a large volume spacer.
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Beclometasona/análogos & derivados , Beclometasona/farmacocinética , Pulmón/metabolismo , Administración por Inhalación , Adolescente , Área Bajo la Curva , Disponibilidad Biológica , Niño , Estudios Cruzados , Femenino , Humanos , Masculino , Tamaño de la Partícula , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
In June 1999, the Food and Drug Administration issued draft guidance for bioequivalence studies for nasal aerosols and nasal sprays for local action. The purpose of this opinion paper is to highlight the need for a balanced scientific debate before this guidance is used by underscoring the areas in the document that are in opposition to prevailing scientific understanding.
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Aerosoles/farmacocinética , Aprobación de Drogas/legislación & jurisprudencia , United States Food and Drug Administration , Absorción , Química Farmacéutica , Aprobación de Drogas/métodos , Sistemas de Liberación de Medicamentos , Guías como Asunto , Humanos , Tamaño de la Partícula , Equivalencia Terapéutica , Estados UnidosRESUMEN
Using an ex vivo alveolar macrophage model, the hypothesis that inhaled preparations of corticosteroids might have important anti-inflammatory effects on cells of the peripheral airway was tested. The tumour necrosis factor (TNF)-alpha-inducing potential of three glycolipid preparations from nonpathogenic (arabinofuranasyl lipoarabinomannan (LAM (Ara-LAM)) and virulent (mannase LAM (ManLAM)) mycobacteria and Gram-negative bacteria (lipopolysaccharide (LPS)), in primary alveolar macrophage preparations was investigated. A novel inhaled chlorofluorocarbon (CFC)-free preparation of beclomethasone dipropionate (hydrofluoroalkane 134a (HFA)-BDP) with increased peripheral lung deposition was investigated for its ability to modulate glycolipidinduced TNF-alpha production by human alveolar macrophages, in comparison with a CFC-containing preparation and placebo. Compared to the basal TNF-alpha bioactivity of 0.72 ng x mL-1 (geometric mean), the TNF-alpha bioactivity in the macrophage preparation increased following incubation with LPS (138 ng x mL-1, p<0.001), AraLAM (12.6 ng-mL-1, p<0.001) and ManLAM (1.42 ng x mL-1, p=0.02). HFA-BDP, administered in vivo, significantly reduced LPS- and ManLAM-induced TNF-alpha production by alveolar macrophages cultured ex vivo. No change in glycolipid-induced TNF-alpha production was observed following in vivo administration of CFC-BDP or HFA-placebo. This is the first demonstration of an immunomodulatory effect on alveolar cells of corticosteroid delivered via metered dose inhaler. The present findings suggest that alveolar deposition of beclomethasone dipropionate is capable of modulating the inflammatory potential of the alveolar macrophage population.
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Beclometasona/administración & dosificación , Líquido del Lavado Bronquioalveolar/citología , Glucocorticoides/administración & dosificación , Macrófagos Alveolares/efectos de los fármacos , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Administración por Inhalación , Adulto , Anciano , Broncoscopía , Células Cultivadas , Femenino , Humanos , Modelos Lineales , Macrófagos Alveolares/metabolismo , Masculino , Persona de Mediana Edad , Valores de Referencia , Sensibilidad y EspecificidadRESUMEN
Since equivalent efficacy is achieved with lower doses of the reformulated beclomethasone dipropionate in the chlorofluorocarbon (CFC)-free propellant HFA-134a (HFA) than with the original CFC-beclomethasone dipropionate formulation, it is possible the HFA-beclomethasone dipropionate may have less safety concerns than the CFC formulation. Despite its chronic use, the steady-state pharmacokinetics of beclomethasone dipropionate has never been studied before. This double-blind study examined adrenal effects and pharmacokinetics after 14 days of dosing with HFA-beclomethasone dipropionate. Forty-three steroid-naïve asthmatic patients were randomised into 5 parallel groups and dosed every 12 h for 14 days with: HFA-placebo; 200, 400 or 800 microg day(-1) HFA-beclomethasone dipropionate; or 800 microg day(-1) CFC-beclomethasone dipropionate. After two weeks of dosing, the 24-h urinary free cortisol of all but one patient remained within the normal range, showing that all doses were well tolerated from a systemic safety perspective. The active HFA-beclomethasone dipropionate treatment groups showed a dose-related fall in 24-h urinary free cortisol. Total-beclomethasone (beclomethasone dipropionate and metabolites) pharmacokinetics after either the first dose of HFA-beclomethasone dipropionate or CFC-beclomethasone dipropionate were not substantially affected by subsequent doses. The extent of drug absorption from 800 microg day(-1) HFA-beclomethasone dipropionate and CFC-beclomethasone dipropionate was in the ratio of 1.7 : 1. A non-linear correlation between 24-h urinary free cortisol and the pharmacokinetic parameters was observed, reflecting smaller changes in 24-h urinary free cortisol than in pharmacokinetics as the dose was increased. No clinically meaningful change in the pharmacokinetics of beclomethasone dipropionate plus metabolites was seen on multiple dosing. The greater systemic availability of HFA-beclomethasone dipropionate was still associated with adrenal effects comparable with that of the CFC formulation at the same dose.
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Glándulas Suprarrenales/efectos de los fármacos , Beclometasona/farmacocinética , Clorofluorocarburos/efectos adversos , Hidrocarburos Fluorados/efectos adversos , Hidrocortisona/orina , Administración por Inhalación , Antiasmáticos/farmacocinética , Antiasmáticos/farmacología , Asma/tratamiento farmacológico , Asma/metabolismo , Beclometasona/farmacología , Disponibilidad Biológica , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Masculino , Nebulizadores y Vaporizadores , Tamaño de la Partícula , Placebos , FumarRESUMEN
We have compared the serum pharmacokinetics of the metabolites of beclomethasone dipropionate after inhalation from chlorofluorocarbon (CFC) and hydrofluoroalkane HFA-134a (HFA) formulations in asthmatic patients. Twenty-three patients completed this open-label, randomized, single-dose, three-period crossover study. Each patient received in separate periods 200 microg or 400 microg HFA-beclomethasone dipropionate, or 400 microg CFC-beclomethasone dipropionate. Venous blood samples were collected over 24 h for the determination of beclomethasone esters and beclomethasone in the serum. Significant differences in pharmacokinetics following HFA- and CFC-beclomethasone dipropionate were observed. Following a 400 microg beclomethasone dipropionate dose, the HFA formulation gave mean maximum concentrations (Cmax) and area under the curve (AUC) values of beclomethasone esters of 1153 pg mL(-1) and 4328 pg h mL(-1), respectively, and beclomethasone Cmax and AUC values of 69 pg mL(-1) and 682 pg h mL(-1), respectively. These values were approximately 2-3-fold those seen with the CFC formulation (beclomethasone esters Cmax and AUC of 380 pg mL(-1) and 1764 pg h mL(-1), respectively; beclomethasone Cmax and AUC of 41 pg ml(-1) and 366 pg h mL(-1), respectively). Beclomethasone esters, the major component of beclomethasone dipropionate in the serum, peaked significantly earlier for the HFA formulation (0.8 h) than for the CFC formulation (2 h). Tests for dose proportionality of beclomethasone esters pharmacokinetics following HFA-beclomethasone dipropionate showed that the two hydrofluoroalkane strengths were proportional. The more rapid and greater efficiency of systemic drug delivery of the HFA formulation compared with the CFC formulation can be explained if most of each inhalation from CFC-beclomethasone dipropionate is swallowed and absorbed orally, whereas most of each inhalation from HFA-beclomethasone dipropionate is absorbed through the lungs. There is a need for comprehensive dose-response efficacy trials, with the use of the steep portion of the dose-response relationship, to evaluate the significance of these pharmacokinetic differences.
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Antiasmáticos/administración & dosificación , Antiasmáticos/farmacocinética , Beclometasona/administración & dosificación , Beclometasona/farmacocinética , Clorofluorocarburos , Adulto , Área Bajo la Curva , Asma/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nebulizadores y Vaporizadores , Método Simple CiegoRESUMEN
Reformulation of beclomethasone dipropionate (BDP) in the chlorofluorocarbon (CFC)-free propellant hydrofluoroalkane-134a (HFA) gave the opportunity to produce a solution formulation that provides a greater total mass of fine drug particles than the current CFC suspension metered dose inhaler (MDI). The HFA-BDP MDI was studied in three pharmacokinetic trials in asthmatic patients. Serum levels of BDP plus metabolites [total beclomethasone (total BOH) assay] were used to test whether the increased fine particle mass of HFA-BDP would result in improved intrapulmonary deposition and subsequent differences in serum profiles. Serum levels, maximum serum concentrations and area under the serum concentration-time curves of total BOH following both single and multiple doses of HFA-BDP were similar to those obtained with approximately twice the dose of CFC-BDP. The observed lower bioavailability of CFC-BDP compared with HFA-BDP could be explained if most of each inhaled dose from the CFC-BDP MDI was swallowed and absorbed from the gastrointestinal tract, while most of each inhaled dose from the HFA-BDP MDI was absorbed from the lungs. Deposition studies have confirmed this explanation. These results suggest that asthmatic patients can be treated with lower total daily doses of drug from HFA-BDP extrafine aerosol than from CFC-BDP.
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Antiinflamatorios/administración & dosificación , Beclometasona/administración & dosificación , Pulmón/efectos de los fármacos , Administración por Inhalación , Adolescente , Adulto , Propelentes de Aerosoles , Antiinflamatorios/farmacocinética , Antiinflamatorios/uso terapéutico , Asma/tratamiento farmacológico , Beclometasona/farmacocinética , Beclometasona/uso terapéutico , Clorofluorocarburos , Estudios Cruzados , Esquema de Medicación , Femenino , Humanos , Hidrocarburos Fluorados , Masculino , Persona de Mediana Edad , Tamaño de la Partícula , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
3M has formulated a new chlorofluorocarbon-free (CFC-free) beclomethasone dipropionate (BDP) metered-dose inhaler (MDI) with the use of the propellant HFA-134a (HFA). Lung deposition studies demonstrated that the HFA BDP MDI delivers to the lungs approximately 56% of the BDP dose (ex-adaptor), a substantially higher percentage than the 5-30% delivered by conventional CFC BDP MDIs. As new sensitive bioanalytical methods are becoming available to quantitate systemic levels of inhaled corticosteroids, pharmacokinetic evaluations are emerging as sensitive and reproducible methods that can be used as a complement to the data obtained from lung deposition studies to assess and compare the performance of MDIs. The present study was designed to determine the beclomethasone (BOH) availability of oral BDP relative to inhaled HFA BDP as a first step to alloy MDI product comparisons in the future. Forty mild asthmatic patients completed this open-label, randomized, single-dose, two-period crossover study. Each patient received an oral dose of BDP (0.2, 0.5, 1, 2 or 5 mg) in one period and an inhaled dose of BDP (0.2 or 0.8 mg) in the other period, with four patients allocated to each of ten different treatment sequences. The BOH availability of orally administered BDP was approximately 40% relative to inhaled HFA BDP. In addition, the fraction of an oral dose that reaches the systemic circulation was estimated from the 40% relative availability and previous lung deposition data to be 0.26. These estimated pharmacokinetic parameters will be used in the future to further characterize the pharmacokinetics of inhaled BDP and to compare the performance of different MDI products.
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Beclometasona/farmacocinética , Administración por Inhalación , Administración Oral , Adolescente , Adulto , Beclometasona/administración & dosificación , Disponibilidad Biológica , Estudios Cruzados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nebulizadores y VaporizadoresRESUMEN
As part of a development program to offer alternatives to chlorofluorocarbon (CFC) containing metered-dose inhalers, beclomethasone dipropionate has been formulated in a CFC-free system at three strengths: 50, 100, and 200 micrograms/actuation ex valve. To measure serum levels and dose proportionality of the beclomethasone derived from beclomethasone dipropionate, 13 mild to moderate asthmatic patients received a single dose of eight inhalations from each strength according to a double-blind crossover design. Seven patients were studied over 4 h and six patients over 12 h. For the total doses of 400, 800, and 1600 micrograms studied over 12 h, Cmax and AUC increased in a ratio of 1:1.8:3.1. A good correlation was seen between the fine-particle mass delivered and the in vivo performance of the three strengths. From a clinical point of view, the predictable increases in serum levels with an increase in dose will permit the clinician to effectively titrate a patient with this product.
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Antiasmáticos/farmacocinética , Antiinflamatorios/farmacocinética , Beclometasona/farmacocinética , Nebulizadores y Vaporizadores/normas , Administración por Inhalación , Adulto , Antiasmáticos/administración & dosificación , Antiinflamatorios/administración & dosificación , Área Bajo la Curva , Asma/sangre , Asma/tratamiento farmacológico , Beclometasona/administración & dosificación , Beclometasona/sangre , Clorofluorocarburos , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Semivida , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Two identical open-label, randomized crossover studies were conducted to compare serum estradiol profiles from the new 12.5- and 25-cm2 once-a-week adhesive patches with those from the 10- and 20-cm2 commercially available twice-a-week Estraderm patches when applied as directed during a 1-week patch-wear period. Both studies were conducted in healthy postmenopausal women; serum estradiol levels were determined by gas chromatography/mass spectroscopy (GC/MS). Although both sizes of both patch treatments produced mean serum estradiol levels in the therapeutic range, the once-a-week patch provided more constant mean levels, avoiding large peak-to-trough fluctuations. As expected, the differences in mean serum estradiol concentrations between the two patch treatments occurred during the second application of the twice-a-week patch. Based on these results, the once-a-week drug in adhesive patch appears to be an acceptable means of hormone replacement therapy.
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Estradiol/sangre , Administración Cutánea , Anciano , Preparaciones de Acción Retardada , Estradiol/administración & dosificación , Femenino , Humanos , Persona de Mediana EdadRESUMEN
The objective of this study was to determine if salbutamol was absorbed from a new salbutamol sulfate chlorofluorocarbon (CFC)-free metered-dose inhaler (MDI). Measurement of HFA-134a, the CFC-free propellant, was included to provide proof of delivery of this MDI. Eight healthy men received two inhalations (90 micrograms salbutamol base equivalents per inhalation ex adapter) from the CFC-free inhaler (MDI A) in period 1 and from a reference CFC inhaler (MDI V) in period 2. Eight postdose samples were collected for the determination of salbutamol serum levels over a 4-h period. Salbutamol levels were not quantifiable in most samples. Four subjects given MDI A and two given MDI V had a few transient salbutamol levels, which occurred in the first hour after dosing, within a narrow range of 1-2 ng/ml and close to the lower limit of detection (1 ng/ml). No pharmacokinetic analyses were possible. Blood samples were also collected after MDI A for propellant quantitation. HFA-134a levels were seen in all subjects, verifying absorption. We conclude that the transient salbutamol serum levels can be attributed to the two-inhalation dose and not to either propellant system.
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Agonistas Adrenérgicos beta/farmacocinética , Albuterol/farmacocinética , Hidrocarburos Fluorados/farmacocinética , Administración por Inhalación , Adolescente , Agonistas Adrenérgicos beta/administración & dosificación , Agonistas Adrenérgicos beta/sangre , Adulto , Propelentes de Aerosoles , Albuterol/administración & dosificación , Albuterol/sangre , Clorofluorocarburos de Metano , Humanos , Hidrocarburos Fluorados/administración & dosificación , Hidrocarburos Fluorados/sangre , Masculino , Persona de Mediana Edad , Nebulizadores y VaporizadoresRESUMEN
A 28-day double-blind parallel group study has been conducted to compare the safety and tolerability of HFA-134a, a chlorofluorocarbon-free propellant in a pressurized metered-dose inhaler (MDI A), with a chlorofluorocarbon propellant (MDI C). Sixteen subjects were randomly assigned to receive one of the two MDIs, either four inhalations four times per day for 14 days or eight inhalations four times a day for 14 days, and were then crossed over to the alternative exposure regime with the same propellant for the next 14-day period. No clinically significant changes occurred in blood pressure, heart rate, electrocardiograms, pulmonary function (FEV1, FVC, FEF25-75%), haematology or serum chemistry. One subject in the MDI A group had elevated eosinophil counts throughout the study; there were no other remarkable clinical laboratory data. Fifty six adverse events were related to the study propellants; 34 of these occurred in the MDI C group and 22 in the MDI A group. For each adverse event no statistically significant differences were detected between propellant systems or between exposure levels. The most frequent adverse event was headache, which was reported by four subjects with each propellant system. Blood samples for HFA-134a in the MDI A group were collected on day 28 to measure systemic absorption. Blood levels of HFA-134a were detected in all subjects given this propellant within 1 min post-exposure, and these levels decreased to one-tenth of the original value by 18 min after the start of exposure. The safety and tolerability of an HFA-134a chlorofluorocarbon-free system was demonstrated over 28 days of exposure in healthy subjects. These negative results are clinically important because they indicate it will be safe to proceed with the study of this chlorofluorocarbon-free system in asthmatic patients.
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Propelentes de Aerosoles/toxicidad , Hidrocarburos Fluorados/toxicidad , Adolescente , Adulto , Propelentes de Aerosoles/farmacocinética , Presión Sanguínea/efectos de los fármacos , Depresores del Sistema Nervioso Central/sangre , Método Doble Ciego , Etanol/sangre , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hidrocarburos Fluorados/farmacocinética , Masculino , Persona de Mediana Edad , Pruebas de Función RespiratoriaRESUMEN
A gas chromatographic procedure with headspace analysis and flame-ionization detection is described for the determination of the chlorofluorocarbon substitute 1,1,1,2-tetrafluoroethane (HFA-134a). A 0.5-2 ml sample of heparinized whole blood from a laboratory animal or human is added directly into a presealed headspace vial from which an equivalent volume of air has been removed. The internal standard 1,1,2,2-tetrafluoroethane is added and the sample frozen until analysis. Chromatographic separation is achieved using a PoraPlot Q porous-layer capillary column. The analytical range is 5.8-3298 ng/ml when 2-ml human blood samples are used. The concentration range of the calibration curve can be easily adapted to accommodate the concentrations expected in either pharmacokinetic or toxicokinetic studies. Automation of the assay permits the maximum number of samples to be processed in a day.