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1.
Ann Oncol ; 29(2): 361-369, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29077785

RESUMEN

Background: Cisplatin-based combination chemotherapy is the standard treatment of advanced urinary tract cancer (aUTC), but 50% of patients are ineligible for cisplatin according to recently published criteria. We used a multinational database to study patterns of chemotherapy utilization in patients with aUTC and determine their impact on survival. Patients and methods: This was a retrospective study of patients with: UTC (bladder, renal pelvis, ureter or urethra); advanced disease (stages T4b and/or N+ and/or M+); urothelial, squamous or adenocarcinoma histology. Primary objective was overall survival (OS). Eligibility-for-cisplatin was defined by Eastern Cooperative Oncology Group performance status ≤ 1, creatinine clearance ≥ 60 ml/min, no hearing loss, no neuropathy and no heart failure. Cox regression multivariate analyses were used to establish independent associations of cisplatin versus noncisplatin-based chemotherapy on OS. Results: 1794 patients treated between 2000 and 2013 at 29 centers were analyzed. Median follow-up was 29.1 months. About 1333 patients (74%) received first-line chemotherapy: the use of first-line chemotherapy was associated with longer OS: [hazard ratio (HR): 1.91, 95% confidence interval (CI): 1.67-2.20]. Type of first-line chemotherapy received was: cisplatin-based 669 (50%), carboplatin-based 399 (30%) and other 265 (20%). Cisplatin use was an independent favorable prognostic factor (HR: 1.54, 95% CI: 1.35-1.77). This benefit was independent of baseline characteristics or comorbidities but was associated with eligibility-for-cisplatin: eligible patients treated with cisplatin lived longer than those who were not (HR: 1.74, 95% CI: 1.36-2.21), while such benefit was not observed among ineligible patients. About 26% of patients who did not receive cisplatin were eligible for this agent. Median OS of ineligible patients was poor irrespective of the chemotherapy used. Conclusions: The importance of applying published criteria of eligibility-for-cisplatin was confirmed in a multinational, real-world setting in aUTC. The reasons for deviations from these criteria set targets to improve adherence. Effective therapies for cisplatin-ineligible patients are needed.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Urológicas/tratamiento farmacológico , Cisplatino/administración & dosificación , Humanos , Estudios Retrospectivos , Resultado del Tratamiento , Neoplasias Urológicas/mortalidad
2.
Ann Oncol ; 28(10): 2472-2480, 2017 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-28961847

RESUMEN

BACKGROUND: Intratumoural heterogeneity (ITH) is well recognised in prostate cancer (PC), but its role in high-risk disease is uncertain. A prospective, single-arm, translational study using targeted multiregion prostate biopsies was carried out to study genomic and T-cell ITH in clinically high-risk PC aiming to identify drivers and potential therapeutic strategies. PATIENTS AND METHODS: Forty-nine men with elevated prostate-specific antigen and multiparametric-magnetic resonance imaging detected PC underwent image-guided multiregion transperineal biopsy. Seventy-nine tumour regions from 25 patients with PC underwent sequencing, analysis of mutations, copy number and neoepitopes combined with tumour infiltrating T-cell subset quantification. RESULTS: We demonstrated extensive somatic nucleotide variation and somatic copy number alteration heterogeneity in high-risk PC. Overall, the mutational burden was low (0.93/Megabase), but two patients had hypermutation, with loss of mismatch repair (MMR) proteins, MSH2 and MSH6. Somatic copy number alteration burden was higher in patients with metastatic hormone-naive PC (mHNPC) than in those with high-risk localised PC (hrlPC), independent of Gleason grade. Mutations were rarely ubiquitous and mutational frequencies were similar for mHNPC and hrlPC patients. Enrichment of focal 3q26.2 and 3q21.3, regions containing putative metastasis drivers, was seen in mHNPC patients. We found evidence of parallel evolution with three separate clones containing activating mutations of ß-catenin in a single patient. We demonstrated extensive intratumoural and intertumoural T-cell heterogeneity and high inflammatory infiltrate in the MMR-deficient (MMRD) patients and the patient with parallel evolution of ß-catenin. Analysis of all patients with activating Wnt/ß-catenin mutations demonstrated a low CD8+/FOXP3+ ratio, a potential surrogate marker of immune evasion. CONCLUSIONS: The PROGENY (PROstate cancer GENomic heterogeneitY) study provides a diagnostic platform suitable for studying tumour ITH. Genetic aberrations in clinically high-risk PC are associated with altered patterns of immune infiltrate in tumours. Activating mutations of Wnt/ß-catenin signalling pathway or MMRD could be considered as potential biomarkers for immunomodulation therapies. CLINICAL TRIALS.GOV IDENTIFIER: NCT02022371.


Asunto(s)
Neoplasias de la Próstata/genética , Neoplasias de la Próstata/inmunología , Biopsia/métodos , Epítopos de Linfocito B/inmunología , Dosificación de Gen , Heterogeneidad Genética , Humanos , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/patología , Masculino , Mutación , Metástasis de la Neoplasia , Neoplasias de la Próstata/patología , Factores de Riesgo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/patología , Linfocitos T/inmunología , Linfocitos T/patología , Vía de Señalización Wnt
3.
Clin Genet ; 88(6): 565-72, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25523111

RESUMEN

Genomic tests are increasingly complex, less expensive, and more widely available with the advent of next-generation sequencing (NGS). We assessed knowledge and perceptions among genetic counselors pertaining to NGS genomic testing via an online survey. Associations between selected characteristics and perceptions were examined. Recent education on NGS testing was common, but practical experience limited. Perceived understanding of clinical NGS was modest, specifically concerning tumor testing. Greater perceived understanding of clinical NGS testing correlated with more time spent in cancer-related counseling, exposure to NGS testing, and NGS-focused education. Substantial disagreement about the role of counseling for tumor-based testing was seen. Finally, a majority of counselors agreed with the need for more education about clinical NGS testing, supporting this approach to optimizing implementation.


Asunto(s)
Concienciación , Comprensión , Asesoramiento Genético , Pruebas Genéticas/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Conocimiento , Adulto , Anciano , Educación Continua/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/diagnóstico , Neoplasias/genética , Competencia Profesional/normas , Competencia Profesional/estadística & datos numéricos , Adulto Joven
4.
Eur J Cancer Care (Engl) ; 24(1): 28-38, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-24467411

RESUMEN

Patient participation in cancer clinical trials is low. Little is known about attitudinal barriers to participation, particularly among patients who may be offered a trial during an imminent initial oncology consult. The aims of the present study were to confirm the presence of proposed subscales of a recently developed cancer clinical trial attitudinal barriers measure, describe the most common cancer clinical trials attitudinal barriers, and evaluate socio-demographic, medical and financial factors associated with attitudinal barriers. A total of 1256 patients completed a survey assessing demographic factors, perceived financial burden, prior trial participation and attitudinal barriers to clinical trials participation. Results of a factor analysis did not confirm the presence of the proposed four attitudinal barriers subscale/factors. Rather, a single factor represented the best fit to the data. The most highly-rated barriers were fear of side-effects, worry about health insurance and efficacy concerns. Results suggested that less educated patients, patients with non-metastatic disease, patients with no previous oncology clinical trial participation, and patients reporting greater perceived financial burden from cancer care were associated with higher barriers. These patients may need extra attention in terms of decisional support. Overall, patients with fewer personal resources (education, financial issues) report more attitudinal barriers and should be targeted for additional decisional support.


Asunto(s)
Toma de Decisiones , Conocimientos, Actitudes y Práctica en Salud , Neoplasias/psicología , Participación del Paciente/psicología , Anciano , Ensayos Clínicos como Asunto , Estudios Transversales , Análisis Factorial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Participación del Paciente/economía , Participación del Paciente/estadística & datos numéricos , Derivación y Consulta , Encuestas y Cuestionarios
6.
Br J Cancer ; 108(4): 812-9, 2013 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-23370209

RESUMEN

BACKGROUND: We studied the association between mammographic calcifications and local recurrence in the ipsilateral breast. METHODS: Case-cohort study within a randomised trial of radiotherapy in breast conservation for ductal cancer in situ of the breast (SweDCIS). We studied mammograms from cases with an ipsilateral breast event (IBE) and from a subcohort randomly sampled at baseline. Lesions were classified as a density without calcifications, architectural distortion, powdery, crushed stone-like or casting-type calcifications. RESULTS: Calcifications representing necrosis were found predominantly in younger women. Women with crushed stone or casting-type microcalcifications had higher histopathological grade and more extensive disease. The relative risk (RR) of a new IBE comparing those with casting-type calcifications to those without calcifications was 2.10 (95% confidence interval (CI) 0.92-4.80). This risk was confined to in situ recurrences; the RR of an IBE associated with casting-type calcifications on the mammogram adjusted for age and disease extent was 16.4 (95% CI 2.20-140). CONCLUSION: Mammographic appearance of ductal carcinoma in situ of the breast is prognostic for the risk of an in situ IBE and may also be an indicator of responsiveness to RT in younger women.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Carcinoma Intraductal no Infiltrante/diagnóstico por imagen , Mamografía , Anciano , Neoplasias de la Mama/patología , Calcinosis/complicaciones , Carcinoma Intraductal no Infiltrante/patología , Estudios de Cohortes , Femenino , Humanos , Persona de Mediana Edad , Necrosis/diagnóstico por imagen , Metástasis de la Neoplasia , Pronóstico , Recurrencia , Medición de Riesgo
7.
J Surg Oncol ; 102(1): 3-9, 2010 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-20578172

RESUMEN

BACKGROUND: Examining >or=12 LN in colon cancer has been suggested as a quality metric. The purpose of this study was to determine whether the 12 LN benchmark is achieved at NCCN centers compared to a US population-based sample. METHODS: Patients with stage I-III disease resected at NCCN centers were identified from a prospective database (n = 718) and were compared to 12,845 stage I-III patients diagnosed in a SEER region. Age, gender, location, stage, number of positive nodes were compared for NCCN and SEER data in regards to number of nodes evaluated. Multivariate logistic regression models were developed to identify factors associated with evaluating 12 LNs. RESULTS: 92% of NCCN and 58% of SEER patients had >or=12 LN evaluated. For patients treated at NCCN centers, factors associated with not meeting the 12 LN target were left-sided tumors, stage I disease and BMI >30. CONCLUSIONS: >or=12 LN are almost always evaluated in NCCN patients. In contrast, this target is achieved in 58% of SEER patients. With longer follow-up of the NCCN cohort we will be able to link this quality metric to patterns of recurrence and survival and thereby better understand whether increasing the number of nodes evaluated is a priority for cancer control.


Asunto(s)
Neoplasias del Colon/patología , Ganglios Linfáticos/patología , Adulto , Anciano , Anciano de 80 o más Años , Benchmarking , Estudios de Cohortes , Bases de Datos Factuales , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Programa de VERF , Adulto Joven
8.
Science ; 263(5145): 380-4, 1994 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-8278812

RESUMEN

Mechanistic information and structure-based design methods have been used to design a series of nonpeptide cyclic ureas that are potent inhibitors of human immunodeficiency virus (HIV) protease and HIV replication. A fundamental feature of these inhibitors is the cyclic urea carbonyl oxygen that mimics the hydrogen-bonding features of a key structural water molecule. The success of the design in both displacing and mimicking the structural water molecule was confirmed by x-ray crystallographic studies. Highly selective, preorganized inhibitors with relatively low molecular weight and high oral bioavailability were synthesized.


Asunto(s)
Azepinas/química , Diseño de Fármacos , Inhibidores de la Proteasa del VIH/química , Administración Oral , Animales , Azepinas/metabolismo , Azepinas/farmacocinética , Azepinas/farmacología , Sitios de Unión , Disponibilidad Biológica , Línea Celular , Cristalografía por Rayos X , Perros , Evaluación Preclínica de Medicamentos , Proteasa del VIH/química , Proteasa del VIH/metabolismo , Inhibidores de la Proteasa del VIH/metabolismo , Inhibidores de la Proteasa del VIH/farmacocinética , Inhibidores de la Proteasa del VIH/farmacología , VIH-1/efectos de los fármacos , VIH-1/fisiología , Enlace de Hidrógeno , Modelos Moleculares , Conformación Molecular , Peso Molecular , Ratas , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Urea , Replicación Viral/efectos de los fármacos
9.
J Surg Oncol ; 100(7): 525-8, 2009 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-19697351

RESUMEN

BACKGROUND: Failing to meet the benchmark of 12 lymph nodes in resection specimens is an indication for adjuvant chemotherapy in stage II colon cancer. METHODS: Among consecutive eligible patients with pathologic stage II colon cancer treated at eight NCI-designated comprehensive cancer centers between September 1, 2005 and February 19, 2008, we analyzed receipt of adjuvant chemotherapy, with less than 12 versus 12+ lymph nodes removed and examined the primary explanatory variable of interest. RESULTS: Among 258 patients, 46% received adjuvant chemotherapy. An oxaliplatin-containing regimen was used 67% of the time. Younger age (<50 years, P < 0.001), presence of lymphovascular invasion (P = 0.007), and higher T stage (P = 0.007) were independently associated with adjuvant chemotherapy use. There was significant inter-institutional variability in practice with the proportion receiving treatment ranging from 17% to 64% (P < 0.05). Notably, presence of less than 12 lymph nodes in the surgical specimen was a strong predictor of treatment (P = 0.008). CONCLUSIONS: Adjuvant chemotherapy use after resection of stage II colon cancer is common, but by no means standard practice at National Comprehensive Cancer Network (NCCN) institutions. More attention to achieving the recommended benchmark for lymph node dissection has the potential to decrease exposure to the toxicity of adjuvant treatment.


Asunto(s)
Quimioterapia Adyuvante/estadística & datos numéricos , Neoplasias del Colon/terapia , Escisión del Ganglio Linfático/estadística & datos numéricos , Factores de Edad , Anciano , Antineoplásicos/administración & dosificación , Neoplasias del Colon/patología , Toma de Decisiones , Femenino , Humanos , Modelos Logísticos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino , Pautas de la Práctica en Medicina
10.
Cancer Chemother Pharmacol ; 62(4): 707-16, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18431572

RESUMEN

PURPOSE: Eribulin mesylate (E7389), a structurally simplified, synthetic analog of the marine natural product halichondrin B, acts by inhibiting microtubule dynamics via mechanisms distinct from those of other tubulin-targeted agents. Eribulin is currently in Phase III clinical trials for the treatment of metastatic breast cancer. Since drug-induced modulation of cytochrome P450 enzymes, particularly CYP3A4, is a frequent cause of drug-drug interactions, we examined the effects of eribulin on the activity and expression of hepatic and recombinant CYP3A4 (rCYP3A4) in vitro. METHODS: Identification of the enzyme(s) responsible for eribulin metabolism was based on compound depletion and metabolite formation in reaction mixtures containing subcellular liver fractions or primary human hepatocytes, plus recombinant Phases I and II metabolic enzymes. The role of the enzyme(s) identified was confirmed using enzyme-selective inhibitors and the correlation with prototypic enzyme activity. The effect of eribulin on enzymatic activity was characterized using both microsomal preparations and recombinant enzymes, while the possible modulation of protein expression was evaluated in primary cultures of human hepatocytes. RESULTS: Eribulin was primarily metabolized by CYP3A4, resulting in the formation of at least four monooxygenated metabolites. In human liver microsomal preparations, eribulin suppressed the activities of CYP3A4-mediated testosterone and midazolam hydroxylation with an apparent K (i) of approximately 20 microM. Eribulin competitively inhibited the testosterone 6beta-hydroxylation, nifedipine dehydration, and R-warfarin 10-hydroxylation activities of rCYP3A4, with an average apparent K (i) of approximately 10 microM. These inhibitions were reversible, with no apparent mechanism-based inactivation. Eribulin did not induce the expression or activities of CYP1A and CYP3A enzymes in human primary hepatocytes, and clinically relevant concentrations of eribulin did not inhibit CYP3A4-mediated metabolism of various therapeutic agents, including carbamazepine, diazepam, paclitaxel, midazolam, tamoxifen, or terfenadine. CONCLUSIONS: Eribulin was predominantly metabolized by CYP3A4. Although eribulin competitively inhibited the testosterone 6beta-hydroxylation, nifedipine dehydration, and R-warfarin 10-hydroxylation activities of rCYP3A4, it did not induce or inhibit hepatic CYP3A4 activity at clinically relevant concentrations. As eribulin does not appear to affect the metabolism of other therapeutic agents by CYP3A4, our data suggest that eribulin would not be expected to inhibit the metabolism of concurrently administered drugs that are metabolized by CYP3A4, suggesting a minimal risk of drug-drug interactions in the clinical setting.


Asunto(s)
Antineoplásicos/farmacología , Citocromo P-450 CYP3A/biosíntesis , Inhibidores Enzimáticos/farmacología , Furanos/farmacología , Hepatocitos/efectos de los fármacos , Cetonas/farmacología , Adulto , Anciano , Antineoplásicos/metabolismo , Células Cultivadas , Niño , Preescolar , Inhibidores del Citocromo P-450 CYP3A , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Inhibidores Enzimáticos/metabolismo , Femenino , Furanos/metabolismo , Hepatocitos/enzimología , Humanos , Recién Nacido , Cetonas/metabolismo , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Persona de Mediana Edad , Nifedipino/metabolismo , Proteínas Recombinantes , Testosterona/metabolismo , Warfarina/metabolismo
11.
Clin Genitourin Cancer ; 13(1): 71-9, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24993933

RESUMEN

BACKGROUND: The differential impact of the number of prior lines of therapy and the setting of prior therapy (perioperative or metastatic) is unclear in advanced urothelial carcinoma. PATIENTS AND METHODS: Ten phase II trials of salvage chemotherapy, biologic agent therapy, or both, enrolling 731 patients, were available. Data on the number of prior lines of therapy and the setting of prior therapy were required in addition to known previously recognized prognostic factors: time from prior chemotherapy, hemoglobin level, performance status, and liver metastasis status. Cox proportional hazards regression was used to evaluate the association of the number of prior lines and prior perioperative therapy with overall survival (OS) as the primary clinical endpoint. Trial was a stratification factor. RESULTS: A total of 711 patients were evaluable. The overall median progression-free survival and OS were 2.7 and 6.8 months, respectively. The number of prior lines was 1 in 559 patients (78.6%), 2 in 111 (15.6%), 3 in 29 (4.1%), 4 in 10 (1.4%), and 5 in 2 (0.3%). Prior perioperative chemotherapy was given to 277 (39.1%) and chemotherapy for metastatic disease to 454 (64.1%). The number of prior lines was not independently associated with OS (hazard ratio, 0.99; 95% CI, 0.86-1.14). Prior perioperative chemotherapy was a favorable factor for OS on univariate but not multivariate analysis. CONCLUSION: The number of prior lines of therapy and prior perioperative chemotherapy were not independently prognostic in patients with urothelial carcinoma receiving salvage therapy. Adoption of these data in salvage therapy trials should enhance accrual, the interpretability of results, and drug development.


Asunto(s)
Quimioterapia/métodos , Terapia Recuperativa/métodos , Neoplasias Urológicas/tratamiento farmacológico , Neoplasias Urológicas/mortalidad , Anciano , Ensayos Clínicos Fase II como Asunto , Humanos , Persona de Mediana Edad , Atención Perioperativa , Estudios Prospectivos , Análisis de Regresión , Análisis de Supervivencia , Resultado del Tratamiento
12.
J Med Chem ; 42(5): 833-48, 1999 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-10072681

RESUMEN

The synthesis and CRF receptor binding affinities of several new series of N-aryltriazolo- and -imidazopyrimidines and -pyridines are described. These cyclized systems were prepared from appropriately substituted diaminopyrimidines or -pyridines by nitrous acid, orthoester, or acyl halide treatment. Variations of amino (ether) pendants and aromatic substituents have defined the structure-activity relationships of these series and resulted in the identification of a variety of high-affinity agents (Ki's < 10 nM). On the basis of this property and lipophilicity differences, six of these compounds (4d,i,n,x, 8k, 9a) were initially chosen for rat pharmacokinetic (PK) studies. Good oral bioavailability, high plasma levels, and duration of four of these compounds (4d,i,n,x) prompted further PK studies in the dog following both iv and oral routes of administration. Results from this work indicated 4i,x had properties we believe necessary for a potential therapeutic agent, and 4i1 has been selected for further pharmacological studies that will be reported in due course.


Asunto(s)
Piridinas/metabolismo , Piridinas/farmacocinética , Pirimidinas/metabolismo , Pirimidinas/farmacocinética , Receptores de Hormona Liberadora de Corticotropina/antagonistas & inhibidores , Administración Oral , Animales , Disponibilidad Biológica , Línea Celular , Perros , Humanos , Ratones , Piridinas/síntesis química , Piridinas/química , Pirimidinas/síntesis química , Pirimidinas/química , Ratas , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Proteínas Recombinantes/metabolismo , Relación Estructura-Actividad
13.
J Clin Pharmacol ; 38(3): 276-82, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9549666

RESUMEN

Modafinil is a novel wake-promoting agent being developed for treatment of excessive daytime sleepiness associated with narcolepsy. An open, 3 x 3 Latin square, randomized, cross-over study was performed in healthy males to compare the pharmacokinetics of single-dose oral modafinil (200 mg) and methylphenidate (40 mg) administered alone or in combination. Blood samples were obtained for analysis of d- and l-threo-methylphenidate and modafinil and its acid and sulfone metabolites. Pharmacokinetic parameters were determined by noncompartmental methods, but could not be evaluated for modafinil sulfone due to plasma levels that were close to the assay quantitation limit. Although sporadic differences in plasma concentrations were observed between treatments, coadministration of modafinil and methylphenidate did not significantly alter the plasma concentrations of modafinil, modafinil acid, modafinil sulfone, or methylphenidate enantiomers compared with administration of these agents alone. Half-life (t1/2), maximum concentration (Cmax), area under the concentration-time curve (AUC0-infinity), total clearance (Cl/F), and apparent volume of distribution (Vd/F) for modafinil and t1/2, Cmax, and AUC0-infinity for modafinil acid were not affected by concomitant administration of methylphenidate. Small but statistically significant increases in time to Cmax (tmax) were observed for modafinil and modafinil acid after methylphenidate coadministration compared with modafinil alone. Modafinil coadministration did not significantly alter the pharmacokinetics of d- or l-threo-methylphenidate, except for a small decrease in Vd/F of l-threo-methylphenidate. Concomitant methylphenidate may cause a delay in the oral absorption of modafinil, but this delay might not be relevant clinically. Coadministration did not alter the extent of oral absorption and disposition of either agent. Therefore, a pharmacokinetic interaction between modafinil and methylphenidate would be unlikely.


Asunto(s)
Adrenérgicos/farmacocinética , Compuestos de Bencidrilo/farmacocinética , Estimulantes del Sistema Nervioso Central/farmacocinética , Metilfenidato/farmacocinética , Adolescente , Adrenérgicos/administración & dosificación , Adrenérgicos/efectos adversos , Adrenérgicos/farmacología , Adulto , Compuestos de Bencidrilo/administración & dosificación , Compuestos de Bencidrilo/efectos adversos , Compuestos de Bencidrilo/farmacología , Estimulantes del Sistema Nervioso Central/administración & dosificación , Estimulantes del Sistema Nervioso Central/efectos adversos , Estimulantes del Sistema Nervioso Central/farmacología , Estudios Cruzados , Método Doble Ciego , Interacciones Farmacológicas , Humanos , Masculino , Metilfenidato/administración & dosificación , Metilfenidato/efectos adversos , Metilfenidato/farmacología , Persona de Mediana Edad , Modafinilo
14.
J Clin Pharmacol ; 39(1): 30-40, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9987698

RESUMEN

A randomized, double-blind, placebo-controlled, ascending-dose study was conducted to evaluate the pharmacokinetic and safety profiles of increasing modafinil doses (200 mg, 400 mg, 600 mg, 800 mg) administered orally over a 7-day period in normal healthy male volunteers. Eight subjects (six modafinil; two placebo) were randomized to each of the four dose groups. Modafinil or a placebo was administered once daily for 7 days. Serial blood samples were obtained following administration of the day 1 and day 7 doses for characterization of pharmacokinetics, and trough samples were obtained prior to dosing on days 2 through 6 to assess the time to reach the steady state. Pharmacokinetic parameters were calculated using noncompartmental methods. Modafinil steady state was reached after three daily doses. Modafinil pharmacokinetics were dose and time independent over the range of 200 mg to 800 mg. Steady-state pharmacokinetics of modafinil were characterized by a rapid oral absorption rate, a low plasma clearance of approximately 50 mL/min, a volume of distribution of approximately 0.8 L/kg, and a long half-life of approximately 15 hr. Modafinil was primarily eliminated by metabolism. Modafinil acid was the major urinary metabolite. Stereospecific pharmacokinetics of modafinil were demonstrated. The d-modafinil enantiomer was eliminated at a threefold faster rate than 1-modafinil. Modafinil 200 mg, 400 mg, and 600 mg doses were generally well tolerated. The modafinil 800 mg dose panel was discontinued after 3 days of treatment due to the observation of increased blood pressure and pulse rate. The safety data from this study suggest that the maximum tolerable single daily oral modafinil dose, without titration, may be 600 mg.


Asunto(s)
Compuestos de Bencidrilo/farmacocinética , Estimulantes del Sistema Nervioso Central/farmacocinética , Adolescente , Adulto , Ansiedad/inducido químicamente , Área Bajo la Curva , Compuestos de Bencidrilo/efectos adversos , Compuestos de Bencidrilo/química , Estimulantes del Sistema Nervioso Central/efectos adversos , Interpretación Estadística de Datos , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Cefalea/inducido químicamente , Humanos , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad , Modafinilo , Trastornos del Inicio y del Mantenimiento del Sueño/inducido químicamente , Estereoisomerismo , Comprimidos , Taquicardia/inducido químicamente
15.
J Clin Pharmacol ; 39(3): 281-8, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10073328

RESUMEN

An open-label, single-center, single-dose, parallel-group study was performed in healthy young males and females as well as healthy elderly males to examine the influence of age and gender on the pharmacokinetics of modafinil following administration of a single 200 mg oral dose. Twelve subjects were enrolled in each of the following three groups: young males, young females, and elderly males. Each fasted (overnight) subject received 2 x 100 mg modafinil tablets. Blood and urine samples were collected at various times up to 72 hours postdose for the determination of plasma and urine levels of modafinil as well as the acid and sulfone metabolites. The plasma concentrations of the individual isomers, d- and l-modafinil, were also determined. Pharmacokinetic parameters were determined by noncompartmental methods. Modafinil was well tolerated at a single oral dose of 200 mg. The most commonly reported adverse events were headache, fever, pharyngitis, and asthenia. There were no clinically meaningful differences with respect to the incidence rate of treatment-emergent adverse events among the young female, young male, and old male groups. Modafinil was rapidly absorbed after oral dosing and slowly cleared (t1/2 approximately 11-14 hr) from the body. Modafinil acid was the major urinary metabolite, which accounted for 35% to 60% of the dose. Results from this study indicated that there were age and gender effects on modafinil clearance processes. In this regard, the clearance rate of modafinil in males decreased with age while young females cleared modafinil at a faster rate than young males. Stereospecific pharmacokinetics of modafinil were also demonstrated. The d-modafinil was eliminated three times faster than the l-modafinil.


Asunto(s)
Compuestos de Bencidrilo/farmacocinética , Estimulantes del Sistema Nervioso Central/farmacocinética , Adulto , Factores de Edad , Anciano , Área Bajo la Curva , Compuestos de Bencidrilo/efectos adversos , Compuestos de Bencidrilo/sangre , Estimulantes del Sistema Nervioso Central/efectos adversos , Femenino , Fiebre/inducido químicamente , Cefalea/inducido químicamente , Humanos , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad , Modafinilo , Faringitis/inducido químicamente , Factores Sexuales , Comprimidos
16.
J Clin Pharmacol ; 38(10): 971-8, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9807980

RESUMEN

An open-label, randomized, crossover study was performed in healthy male volunteers to evaluate the potential pharmacokinetic and pharmacodynamic interactions and tolerability of single oral doses of modafinil (200 mg) and dextroamphetamine (10 mg). Blood samples were collected for determination of plasma levels of modafinil, the acid and sulfone metabolites of modafinil, and dextroamphetamine at intervals through 48 hours after administration for each treatment. Vital signs (blood pressure and pulse rate) were measured through 48 hours, and electrocardiograms were measured through 24 hours after administration. Pharmacokinetic parameters were determined using noncompartmental methods. The data collected in this study of 24 healthy volunteers suggest that concomitant administration of single oral doses of modafinil and dextroamphetamine has no clinically significant effects on the pharmacokinetic profile of either agent. Although there was a slightly greater incidence of adverse events when modafinil and dextroamphetamine were administered together, the concomitant administration of the two drugs was well tolerated.


Asunto(s)
Compuestos de Bencidrilo/administración & dosificación , Compuestos de Bencidrilo/farmacocinética , Estimulantes del Sistema Nervioso Central/administración & dosificación , Estimulantes del Sistema Nervioso Central/farmacocinética , Dextroanfetamina/administración & dosificación , Dextroanfetamina/farmacocinética , Adulto , Área Bajo la Curva , Presión Sanguínea/efectos de los fármacos , Intervalos de Confianza , Estudios Cruzados , Quimioterapia Combinada , Electrocardiografía , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Análisis de los Mínimos Cuadrados , Masculino , Persona de Mediana Edad , Modafinilo , Estadísticas no Paramétricas
17.
J Pharm Pharmacol ; 48(5): 492-7, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8799873

RESUMEN

EXP3312, 2-n-propyl-4-chloro-1-[(2'-(1H-tetrazol-5-yl)-biphenyl-4-yl) methyl]imidazole-5-carboxylaldehyde, is a non-peptide angiotensin II (AII) AT1-receptor antagonist. In the rabbit isolated aorta EXP3312 inhibited the contractile response to AII competitively with a pA2 value of 8.24. In renal hypertensive rats EXP3312 reduced blood pressure with intravenous and oral ED30 values of 0.19 and 0.14 mg kg-1, respectively. It also reduced blood pressure in frusemide-treated dogs when administered orally at 1 and 3 mg kg-1. In rats and dogs, the absolute oral bioavailability of EXP3312 averaged 60 and 28%, respectively. When EXP3312 was administered intravenously to rats and dogs the plasma elimination half-lives were 1.20 and 2.52 h, respectively. In rats and dogs EXP3312 was metabolized to an active metabolite M1, 2-n-propyl-4-chloro-1-[(2'-(1H-tetrazol-5-yl)-biphenyl-4-yl) methyl]imidazole-5-carboxylic acid. M1 is about ten times more potent than EXP3312 in renal hypertensive rats; the intravenous ED30 value was 0.02 mg kg-1. Because high plasma levels of M1 were found in rats after oral administration of EXP3312, it is likely that M1 contributes to the long duration of the antihypertensive effects of EXP3312 in renal hypertensive rats. The results show that EXP3312 is potent, orally active, competitive and selective AT1-receptor antagonist and a potent antihypertensive agent; it is likely to be therapeutically useful in the treatment of hypertension and congestive heart failure.


Asunto(s)
Angiotensina II/antagonistas & inhibidores , Antagonistas de Receptores de Angiotensina , Antihipertensivos/farmacología , Compuestos de Bifenilo/farmacología , Imidazoles/farmacología , Tetrazoles/farmacología , Administración Oral , Angiotensina II/farmacología , Animales , Antihipertensivos/administración & dosificación , Antihipertensivos/sangre , Antihipertensivos/farmacocinética , Aorta/efectos de los fármacos , Compuestos de Bifenilo/administración & dosificación , Compuestos de Bifenilo/sangre , Compuestos de Bifenilo/farmacocinética , Presión Sanguínea/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Perros , Relación Dosis-Respuesta a Droga , Femenino , Hipertensión Renal/fisiopatología , Imidazoles/administración & dosificación , Imidazoles/sangre , Imidazoles/farmacocinética , Técnicas In Vitro , Infusiones Intravenosas , Masculino , Contracción Muscular/efectos de los fármacos , Conejos , Ratas , Ratas Sprague-Dawley , Tetrazoles/administración & dosificación , Tetrazoles/sangre , Tetrazoles/farmacocinética
20.
Anal Biochem ; 298(1): 40-9, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11673893

RESUMEN

A sensitive assay using high-performance liquid chromatography tandem mass spectrometry (MS/MS) has been established for the quantitative analysis of cytochrome P450 form-specific activities using warfarin as a probe substrate. Four metabolites, 6-, 7-, 8-, and 10-hydroxywarfarin, were chromatographically resolved within 10 min using gradient mobile phases. The mass spectrometry was operated under negative ionization mode. The MS/MS product ion spectra of warfarin and the metabolites were generated using collision-activated dissociation and interpreted. The abundant product ions of the metabolites were selected for quantification applying multiple reaction monitoring. Quantification was based on a quadratic or power curve of the peak area ratio of the metabolite over the internal standard against the respective concentration of the metabolite. This assay has been validated from 2 to 1000 nM for 10-hydroxywarfarin and from 2 to 5000 nM for 6-, 7-, and 8-hydroxywarfarin and successfully applied to evaluate cytochrome P450-mediated drug-drug interactions in vitro using human hepatocytes and liver microsomal preparations.


Asunto(s)
Cromatografía Liquida/métodos , Sistema Enzimático del Citocromo P-450/metabolismo , Espectrometría de Masas/métodos , Warfarina/análogos & derivados , Warfarina/análisis , Warfarina/química , Calibración/normas , Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Hepatocitos/enzimología , Humanos , Cetoconazol/farmacología , Microsomas Hepáticos/enzimología , Dibenzodioxinas Policloradas/farmacología , Estereoisomerismo , Warfarina/metabolismo
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