RESUMEN
AIMS: To evaluate the safety and pharmacokinetics of naringenin in healthy adults consuming whole-orange (Citrus sinensis) extract. METHODS AND METHODS: In a single-ascending-dose randomized crossover trial, 18 adults ingested doses of 150 mg (NAR150), 300 mg (NAR300), 600 mg (NAR600) and 900 mg (NAR900) naringenin or placebo. Each dose or placebo was followed by a wash-out period of at least 1 week. Blood safety markers were evaluated pre-dose and 24 hours post-dose. Adverse events (AEs) were recorded. Serum naringenin concentrations were measured before and over 24 hours following ingestion of placebo, NAR150 and NAR600. Four- and 24-hour serum measurements were obtained after placebo, NAR300 and NAR900 ingestion. Data were analysed using a mixed-effects linear model. RESULTS: There were no relevant AEs or changes in blood safety markers following ingestion of any of the naringenin doses. The pharmacokinetic variables were: maximal concentration: 15.76 ± 7.88 µM (NAR150) and 48.45 ± 7.88 µM (NAR600); time to peak: 3.17 ± 0.74 hours (NAR150) and 2.41 ± 0.74 hours (NAR600); area under the 24-hour concentration-time curve: 67.61 ± 24.36 µM × h (NAR150) and 199.05 ± 24.36 µM × h (NAR600); and apparent oral clearance: 10.21 ± 2.34 L/h (NAR150) and 13.70 ± 2.34 L/h (NAR600). Naringenin half-life was 3.0 hours (NAR150) and 2.65 hours (NAR600). After NAR300 ingestion, serum concentrations were 10.67 ± 5.74 µM (4 hours) and 0.35 ± 0.30 µM (24 hours). After NAR900 ingestion, serum concentrations were 43.11 ± 5.26 µM (4 hours) and 0.24 ± 0.30 µM (24 hours). CONCLUSIONS: Ingestion of 150 to 900 mg doses of naringenin is safe in healthy adults, and serum concentrations are proportional to the dose administered. Since naringenin (8 µM) is effective in primary human adipocytes, ingestion of 300 mg naringenin twice/d will likely elicit a physiological effect.
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Flavanonas/administración & dosificación , Flavanonas/farmacocinética , Administración Oral , Adulto , Área Bajo la Curva , Citrus/química , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Flavanonas/efectos adversos , Semivida , Humanos , Masculino , Tasa de Depuración Metabólica , Persona de Mediana Edad , Extractos Vegetales/química , Adulto JovenRESUMEN
BACKGROUND: During sepsis, higher plasma cell-free hemoglobin (CFH) levels portend worse outcomes. In sepsis models, plasma proteins that bind CFH improve survival. In our canine antibiotic-treated Staphylococcus aureus pneumonia model, with and without red blood cell (RBC) exchange transfusion, commercial human haptoglobin (Hp) concentrates bound and compartmentalized CFH intravascularly, increased CFH clearance, and lowered iron levels, improving shock, lung injury, and survival. We now investigate in our model how very high CFH levels and treatment time affect Hp's beneficial effects. MATERIALS AND METHODS: Two separate canine pneumonia sepsis Hp studies were undertaken: one with exchange transfusion of RBCs after prolonged storage to raise CFH to very high levels and another with rapidly lethal sepsis alone to shorten time to treat. All animals received continuous standard intensive care unit supportive care for 96 hours. RESULTS: Older RBCs markedly elevated plasma CFH levels and, when combined with Hp therapy, created supraphysiologic CFH-Hp complexes that did not increase CFH or iron clearance or improve lung injury and survival. In a rapidly lethal bacterial challenge model without RBC transfusion, Hp binding did not increase clearance of complexes or iron or show benefits seen previously in the less lethal model. DISCUSSION: High-level CFH-Hp complexes may impair clearance mechanisms and eliminate Hp's beneficial effect during sepsis. Rapidly lethal sepsis narrows the therapeutic window for CFH and iron clearance, also decreasing Hp's beneficial effects. In designing clinical trials, dosing and kinetics may be critical factors if Hp infusion is used to treat sepsis.
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Haptoglobinas/uso terapéutico , Hemoglobinas/metabolismo , Neumonía Estafilocócica/tratamiento farmacológico , Neumonía Estafilocócica/metabolismo , Choque Séptico/tratamiento farmacológico , Choque Séptico/metabolismo , Animales , Modelos Animales de Enfermedad , Perros , Transfusión de Eritrocitos , Neumonía Estafilocócica/terapia , Sepsis/tratamiento farmacológico , Sepsis/metabolismo , Sepsis/terapia , Choque Séptico/terapiaRESUMEN
During the last half-century, numerous antiinflammatory agents were tested in dozens of clinical trials and have proven ineffective for treating septic shock. The observation in multiple studies that cell-free hemoglobin (CFH) levels are elevated during clinical sepsis and that the degree of increase correlates with higher mortality suggests an alternative approach. Human haptoglobin binds CFH with high affinity and, therefore, can potentially reduce iron availability and oxidative activity. CFH levels are elevated over approximately 24-48 hours in our antibiotic-treated canine model of S. aureus pneumonia that simulates the cardiovascular abnormalities of human septic shock. In this 96-hour model, resuscitative treatments, mechanical ventilation, sedation, and continuous care are translatable to management in human intensive care units. We found, in this S. aureus pneumonia model inducing septic shock, that commercial human haptoglobin concentrate infusions over 48-hours bind canine CFH, increase CFH clearance, and lower circulating iron. Over the 96-hour study, this treatment was associated with an improved metabolic profile (pH, lactate), less lung injury, reversal of shock, and increased survival. Haptoglobin binding compartmentalized CFH to the intravascular space. This observation, in combination with increasing CFHs clearance, reduced available iron as a potential source of bacterial nutrition while decreasing the ability for CFH and iron to cause extravascular oxidative tissue injury. In contrast, haptoglobin therapy had no measurable antiinflammatory effect on elevations in proinflammatory C-reactive protein and cytokine levels. Haptoglobin therapy enhances normal host defense mechanisms in contrast to previously studied antiinflammatory sepsis therapies, making it a biologically plausible novel approach to treat septic shock.
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Haptoglobinas/farmacología , Lesión Pulmonar/tratamiento farmacológico , Neumonía/tratamiento farmacológico , Choque Séptico/tratamiento farmacológico , Animales , Antibacterianos , Antiinflamatorios/farmacología , Análisis de los Gases de la Sangre , Anomalías Cardiovasculares , Citocinas , Modelos Animales de Enfermedad , Perros , Haptoglobinas/uso terapéutico , Hematócrito , Humanos , Inmunidad Innata , Hierro , Estimación de Kaplan-Meier , Neumonía/microbiología , Neumonía/mortalidad , Arteria Pulmonar , Staphylococcus aureusRESUMEN
Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is one of the most devastating of adverse drug reactions (ADRs) and was, until recently, essentially unpredictable. With the discovery of several risk alleles for drug-induced SJS/TEN and the demonstration of effectiveness of screening in reducing incidence, the stage is set for implementation of preventive strategies in populations at risk. Yet much remains to be learned about this potentially fatal complication of commonly used drugs.
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Predisposición Genética a la Enfermedad/genética , Pruebas Genéticas , Síndrome de Stevens-Johnson/genética , Predisposición Genética a la Enfermedad/prevención & control , Humanos , Incidencia , Necrosis , Valor Predictivo de las Pruebas , Síndrome de Stevens-Johnson/epidemiología , Síndrome de Stevens-Johnson/prevención & controlRESUMEN
The National Institutes of Health Clinical Center (NIH CC) is the largest hospital in the United States devoted entirely to clinical research, with a highly diverse spectrum of patients. Patient safety and clinical quality are major goals of the hospital, and therapy is often complicated by multiple cotherapies and comorbidities. To this end, we implemented a pharmacogenomics program in 2 phases. In the first phase, we implemented genotyping for HLA-A and HLA-B gene variations with clinical decision support (CDS) for abacavir, carbamazepine, and allopurinol. In the second phase, we implemented genotyping for drug-metabolizing enzymes and transporters: SLCO1B1 for CDS of simvastatin and TPMT for CDS of mercaptopurine, azathioprine, and thioguanine. The purpose of this review is to describe the implementation process, which involves clinical, laboratory, informatics, and policy decisions pertinent to the NIH CC.
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Investigación Biomédica/organización & administración , National Institutes of Health (U.S.)/organización & administración , Farmacogenética/métodos , Sistemas de Apoyo a Decisiones Clínicas , Genotipo , Humanos , Informática Médica , Política Organizacional , Estados UnidosRESUMEN
Pharmacogenetics (PG) examines gene variations for drug disposition, response, or toxicity. At the National Institutes of Health Clinical Center (NIH CC), a multidepartment Pharmacogenetics Testing Implementation Committee (PGTIC) was established to develop clinical decision support (CDS) algorithms for abacavir, carbamazepine, and allopurinol, medications for which human leukocyte antigen (HLA) variants predict severe hypersensitivity reactions. Providing PG CDS in the electronic health record (EHR) during order entry could prevent adverse drug events. Medical Logic Module (MLM) programming was used to implement PG CDS in our EHR. The MLM checks to see if an HLA sequence-based gene test is ordered. A message regarding test status (result present, absent, pending, or test not ordered) is displayed on the order form, and the MLM determines if the prescriber can place the order, place it but require an over-ride reason, or be blocked from placing the order. Since implementation, more than 725 medication orders have been placed for over 230 patients by 154 different prescribers for the three drugs included in our PG program. Prescribers commonly used an over-ride reason when placing the order mainly because patients had been receiving the drug without reaction before implementation of the CDS program. Successful incorporation of PG CDS into the NIH CC EHR required a coordinated, interdisciplinary effort to ensure smooth activation and a positive effect on patient care. Prescribers have adapted to using the CDS and have ordered PG testing as a direct result of the implementation.
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Quimioterapia Asistida por Computador , Registros Electrónicos de Salud , Farmacogenética , Algoritmos , Sistemas de Apoyo a Decisiones Clínicas , Genotipo , Antígenos HLA/genética , Humanos , Sistemas de Entrada de Órdenes Médicas , Medicina de Precisión/métodos , Integración de Sistemas , Interfaz Usuario-ComputadorRESUMEN
Blood-urea nitrogen, serum creatinine and urine output have long been used as markers of kidney function despite their known limitations. In the past few years, a number of novel biomarkers have been identified in the urine and blood that can detect kidney injury early. Although, to date, none of these biomarkers are in clinical use, many have been validated as reliable and sensitive, allowing detection of kidney injury before serum creatinine levels rise and urine output drops. These markers have been evaluated in great detail in animal models and to a lesser extent in humans in postcardiopulmonary bypass and sepsis. There is relatively scarse data on the use of these biomarkers in the detection of kidney injury associated with the use of pharmacologic agents. The purpose of this article is to summarize these data and highlight the potential utility of these biomarkers in nephropharmacology.
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Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/diagnóstico , Biomarcadores Farmacológicos/sangre , Biomarcadores Farmacológicos/orina , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Lesión Renal Aguda/sangre , Lesión Renal Aguda/orina , Animales , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/sangre , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/orina , Humanos , Riñón/efectos de los fármacosRESUMEN
Lassa fever is an acute viral hemorrhagic illness; the virus is endemic in West Africa and also of concern with regard to bioterrorism. Transmission of Lassa virus between humans may occur through direct contact with infected blood or bodily secretions. Oral administration of the antiviral drug ribavirin is often considered for postexposure prophylaxis, but no systematically collected data or uniform guidelines exist for this indication. Furthermore, the relatively low secondary attack rates for Lassa fever, the restriction of the area of endemicity to West Africa, and the infrequency of high-risk exposures make it unlikely that controlled prospective efficacy trials will ever be possible. Recommendations for postexposure use of ribavirin can therefore be made only on the basis of a thorough understanding and logical extrapolation of existing data. Here, we review the pertinent issues and propose guidelines based on extensive review of the literature, as well as our experience in this field. We recommend oral ribavirin postexposure prophylaxis for Lassa fever exclusively for definitive high-risk exposures. These guidelines may also serve for exposure to other hemorrhagic fever viruses susceptible to ribavirin.
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Antivirales/administración & dosificación , Quimioprevención/métodos , Fiebre de Lassa/prevención & control , Guías de Práctica Clínica como Asunto , Ribavirina/administración & dosificación , Humanos , Fiebre de Lassa/tratamiento farmacológicoRESUMEN
BACKGROUND: To our knowledge, the antiviral activity of pegylated interferon alfa-2a has not been studied in participants with untreated human immunodeficiency virus type 1 (HIV-1) infection but without chronic hepatitis C virus (HCV) infection. METHODS: Untreated HIV-1-infected volunteers without HCV infection received 180 microg of pegylated interferon alfa-2a weekly for 12 weeks. Changes in plasma HIV-1 RNA load, CD4(+) T cell counts, pharmacokinetics, pharmacodynamic measurements of 2',5'-oligoadenylate synthetase (OAS) activity, and induction levels of interferon-inducible genes (IFIGs) were measured. Nonparametric statistical analysis was performed. RESULTS: Eleven participants completed 12 weeks of therapy. The median plasma viral load decrease and change in CD4(+) T cell counts at week 12 were 0.61 log(10) copies/mL (90% confidence interval [CI], 0.20-1.18 log(10) copies/mL) and -44 cells/microL (90% CI, -95 to 85 cells/microL), respectively. There was no correlation between plasma viral load decreases and concurrent pegylated interferon plasma concentrations. However, participants with larger increases in OAS level exhibited greater decreases in plasma viral load at weeks 1 and 2 (r = -0.75 [90% CI, -0.93 to -0.28] and r = -0.61 [90% CI, -0.87 to -0.09], respectively; estimated Spearman rank correlation). Participants with higher baseline IFIG levels had smaller week 12 decreases in plasma viral load (0.66 log(10) copies/mL [90% CI, 0.06-0.91 log(10) copies/mL]), whereas those with larger IFIG induction levels exhibited larger decreases in plasma viral load (-0.74 log(10) copies/mL [90% CI, -0.93 to -0.21 log(10) copies/mL]). CONCLUSION: Pegylated interferon alfa-2a was well tolerated and exhibited statistically significant anti-HIV-1 activity in HIV-1-monoinfected patients. The anti-HIV-1 effect correlated with OAS protein levels (weeks 1 and 2) and IFIG induction levels (week 12) but not with pegylated interferon concentrations.
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Fármacos Anti-VIH/efectos adversos , Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , Interferón-alfa/efectos adversos , Interferón-alfa/uso terapéutico , Polietilenglicoles/efectos adversos , Polietilenglicoles/uso terapéutico , 2',5'-Oligoadenilato Sintetasa/metabolismo , Adulto , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/farmacocinética , Recuento de Linfocito CD4 , Perfilación de la Expresión Génica , Infecciones por VIH/virología , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Interferón-alfa/farmacocinética , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Polietilenglicoles/farmacocinética , ARN Viral/sangre , Proteínas Recombinantes , Resultado del Tratamiento , Carga ViralRESUMEN
BACKGROUND: Chronic renal failure (CRF) has been shown to significantly reduce the nonrenal clearance and alter bioavailability of drugs predominantly metabolized by the liver and intestine. OBJECTIVES: The purpose of this article is to review all significant animal and clinical studies dealing with the effect of CRF on drug metabolism and transport. METHODS: A search of the National Library of Medicine PubMed was done with terms such as chronic renal failure, cytochrome P450 [CYP], liver metabolism, efflux drug transport and uptake transport, including relevant articles back to 1969. RESULTS: Animal studies in CRF have shown a significant downregulation (40-85%) of hepatic and intestinal CYP metabolism. High levels of parathyroid hormone, cytokines and uremic toxins have been shown to reduce CYP activity. Phase II reactions and drug transporters such as P-glycoprotein and organic anion transporting polypeptide are also affected. CONCLUSION: CRF alters intestinal, renal and hepatic drug metabolism and transport producing a clinically significant impact on drug disposition and increasing the risk for adverse drug reactions.
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Sistema Enzimático del Citocromo P-450/metabolismo , Fallo Renal Crónico/metabolismo , Preparaciones Farmacéuticas/metabolismo , Animales , Disponibilidad Biológica , Transporte Biológico , Ensayos Clínicos como Asunto , Regulación hacia Abajo , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Humanos , FarmacocinéticaRESUMEN
BACKGROUND: Concomitant use of antiretroviral (ARV) and hormonal contraceptives may change the metabolism of each and the resulting safety profiles. We evaluated the safety and tolerability of depot medroxyprogesterone acetate (DMPA) among women on ARV. STUDY DESIGN: HIV-infected women on selected ARV regimens or no ARV were administered DMPA 150 mg intramuscularly and evaluated for 12 weeks for adverse events, changes in CD4+ count and HIV RNA levels, and ovulation. RESULTS: Seventy evaluable subjects were included, 16 on nucleoside only or no ARV, 21 on nelfinavir-containing regimens, 17 on efavirenz-containing regimens and 16 on nevirapine-containing regimens. Nine Grade 3 or 4 adverse events occurred in seven subjects; none were judged related to DMPA. The most common findings possibly related to DMPA were abnormal vaginal bleeding (nine, 12.7%), headache (three, 4.2%), abdominal pain, mood changes, insomnia, anorexia and fatigue, each occurring in two (2.9%) subjects. No significant changes in CD4+ count or HIV RNA levels occurred with DMPA. No evidence of ovulation was detected, and no pregnancies occurred. CONCLUSIONS: The clinical profile associated with DMPA administration in HIV-infected women, most on ARV, appears similar to that seen in HIV-uninfected women. DMPA prevented ovulation and did not affect CD4+ counts or HIV RNA levels. In concert with previously published DMPA/ARV interaction data, these data suggest that DMPA can be used safely by HIV-infected women on the ARV studied.
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Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Anticonceptivos Femeninos/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Acetato de Medroxiprogesterona/administración & dosificación , Inhibición de la Ovulación/efectos de los fármacos , Adulto , Alquinos , Fármacos Anti-VIH/efectos adversos , Benzoxazinas/administración & dosificación , Benzoxazinas/efectos adversos , Recuento de Linfocito CD4 , Anticonceptivos Femeninos/efectos adversos , Ciclopropanos , Interacciones Farmacológicas , Femenino , Humanos , Inyecciones Intramusculares , Acetato de Medroxiprogesterona/efectos adversos , Nelfinavir/administración & dosificación , Nelfinavir/efectos adversos , Nevirapina/administración & dosificación , Nevirapina/efectos adversos , ARN Viral/sangre , Seguridad , Carga ViralRESUMEN
Increased dietary linoleic acid has been associated with reduced blood pressure in clinical and animal studies possibly mediated by prostaglandins. Urinary linoleate and prostaglandin metabolite excretion were investigated in subjects exposed to a salt-loading/salt-depletion regimen. Twelve healthy subjects were recruited from the New Orleans population (before Hurricaine Katrina) and admitted to the Tulane-Louisiana State University-Charity Hospital General Clinical Research Center after a 5-day outpatient lead-in phase on a 160-mmol sodium diet. On inpatient day 1, the subjects were maintained on the 160-mmol sodium diet, and a 24-hour urine specimen was collected. On day 2, the subjects received 2 L of IV normal saline over 4 hours and continued on a 160-mmol Na(+) diet (total: 460 mmol of sodium). Two 12-hour urine collections were obtained. On day 3, the subjects received three 40-mg oral doses of furosemide, two 12-hour urine collections were obtained, and the subjects were given a 10-mmol sodium diet. Urinary oxidized lipids were measured by high-performance liquid chromatography-tandem quadrupole mass spectroscopy. The excretion of the urinary linoleate metabolites, dihydroxyoctadecamonoenoic acids, and trihydroxyoctadecamonoenoic acids increased significantly during intravenous salt loading as compared with day 1 and the salt-depleted periods. The urinary excretion of 6-keto- prostaglandin F1alpha was unaffected by salt loading but was dramatically increased 7- to 10-fold by salt depletion. Prostaglandin E2 excretion was positively correlated with sodium excretion. The salt-stimulated production of linoleic acid diols and triols may inhibit tubular sodium reabsorption, thereby assisting in the excretion of the sodium load.
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Ácido Linoleico/orina , Sodio en la Dieta/farmacología , 6-Cetoprostaglandina F1 alfa/orina , Adulto , Dinoprostona/orina , Femenino , Furosemida/farmacología , Humanos , Ácido Linoleico/metabolismo , Masculino , Persona de Mediana Edad , Sodio/orina , Inhibidores del Simportador de Cloruro Sódico y Cloruro Potásico/farmacología , Factores de TiempoRESUMEN
Renal involvement in patients with multiple myeloma complicates their treatment and shortens their life-span. The main renal lesion is a tubulointerstitial transformation with fibrosis, frequently associated with cast formation in the distal nephron that results from co-precipitation of pathological immunoglobulin light chains with Tamm-Horsfall proteins. The human renal proximal tubular reabsorption of excessive light chains by endocytosis causes cellular protein overload and activates the transcription factor nuclear factor kappa B (NFkappaB). The activation of NFkappaB promotes the synthesis of inflammatory cytokines and activates signaling pathways, such as mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase 1/2, Jun kinase, and p38 MAPK, thus promoting interstitial inflammation and fibrosis. We tested the concept that pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the secretin/vasoactive intestinal peptide family, could prevent the development of cast nephropathies. PACAP38 inhibited myeloma light chain-induced proinflammatory cytokine expression with greater potency than dexamethasone, and attenuated the resulting cell damage in the renal proximal tubule epithelial cells. The results indicated that its effects are mediated through inhibition of phosphorylation of p38 MAPK and nuclear translocation of the p50 subunit of NFkappaB via both the PAC(1) and VPAC(1) receptors. PACAP was also shown to be efficacious in other common in vivo animal models for kidney hypertrophies, including streptozotocin-induced diabetic nephropathy and gentamicin-induced nephrotoxicity. Thus, our studies suggest that PACAP38 could be used as a cytoprotective agent that would be effective in the treatment of renal tubule injury in multiple myeloma and other chronic kidney diseases.
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Enfermedades Renales/enzimología , Mieloma Múltiple/enzimología , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/metabolismo , Animales , Gentamicinas/farmacología , Humanos , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/efectos adversosRESUMEN
We have recently shown significant renoprotective effects with the administration of pituitary adenylate cyclase-activating polypeptide (PACAP) in models of myeloma kidney. PACAP markedly inhibited the production of proinflammatory cytokines stimulated by immunoglobulin light chains in human renal proximal tubule epithelial cells and in the kidneys of rats infused with myeloma light chains. PACAP was also shown to suppress the proliferation of human kappa and lambda light chain-secreting multiple myeloma-derived cells. In this case study, an 81-year-old male patient with active multiple myeloma and myeloma kidney was infused intravenously with synthetic human PACAP38 at a rate of 4 pmol/kg/min for 120 min. The continuous infusion increased the level of PACAP38 in blood, with a plateau at about 0.2 nM during the infusion. The level of PACAP in the blood rapidly declined after the cessation of administration with a half-life of about 5-10 min. The continuous infusion did not significantly alter the basal glucose level, blood gases or blood pressure. There was a large reduction in free lambda light chains in urine after the start of the treatment with PACAP. These studies show that PACAP can be safely used in humans and suggest that it could be used as a novel therapeutic agent for the treatment of multiple myeloma and myeloma kidney.
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Mieloma Múltiple/tratamiento farmacológico , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/uso terapéutico , Insuficiencia Renal/tratamiento farmacológico , Anciano de 80 o más Años , Citocinas/metabolismo , Humanos , Cadenas lambda de Inmunoglobulina/orina , Infusiones Intravenosas , Masculino , Mieloma Múltiple/complicaciones , Mieloma Múltiple/metabolismo , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/administración & dosificación , Polipéptido Hipofisario Activador de la Adenilato-Ciclasa/sangre , Insuficiencia Renal/etiología , Insuficiencia Renal/orina , Resultado del TratamientoRESUMEN
OBJECTIVES: To determine: (1) the pharmacokinetics and safety of an investigational aminoquinoline active against multidrug-resistant malaria parasites (AQ-13), including its effects on the QT interval, and (2) whether it has pharmacokinetic and safety profiles similar to chloroquine (CQ) in humans. DESIGN: Phase I double-blind, randomized controlled trials to compare AQ-13 and CQ in healthy volunteers. Randomizations were performed at each step after completion of the previous dose. SETTING: Tulane-Louisiana State University-Charity Hospital General Clinical Research Center in New Orleans. PARTICIPANTS: 126 healthy adults 21-45 years of age. INTERVENTIONS: 10, 100, 300, 600, and 1,500 mg oral doses of CQ base in comparison with equivalent doses of AQ-13. OUTCOME MEASURES: Clinical and laboratory adverse events (AEs), pharmacokinetic parameters, and QT prolongation. RESULTS: No hematologic, hepatic, renal, or other organ toxicity was observed with AQ-13 or CQ at any dose tested. Headache, lightheadedness/dizziness, and gastrointestinal (GI) tract-related symptoms were the most common AEs. Although symptoms were more frequent with AQ-13, the numbers of volunteers who experienced symptoms with AQ-13 and CQ were similar (for AQ-13 and CQ, respectively: headache, 17/63 and 10/63, p = 0.2; lightheadedness/dizziness, 11/63 and 8/63, p = 0.6; GI symptoms, 14/63 and 13/63; p = 0.9). Both AQ-13 and CQ exhibited linear pharmacokinetics. However, AQ-13 was cleared more rapidly than CQ (respectively, median oral clearance 14.0-14.7 l/h versus 9.5-11.3 l/h; p < or = 0.03). QTc prolongation was greater with CQ than AQ-13 (CQ: mean increase of 28 ms; 95% confidence interval [CI], 18 to 38 ms, versus AQ-13: mean increase of 10 ms; 95% CI, 2 to 17 ms; p = 0.01). There were no arrhythmias or other cardiac AEs with either AQ-13 or CQ. CONCLUSIONS: These studies revealed minimal differences in toxicity between AQ-13 and CQ, and similar linear pharmacokinetics.
RESUMEN
BACKGROUND: The cytochrome P450 (CYP) epoxygenase pathway produces arachidonic acid metabolites that are vasoactive, that affect renal sodium handling, and that have been proposed to play a mechanistic role in hypertension. Multiple single nucleotide polymorphisms (SNP) in CYP2C8, 2C9, 2J2 and soluble epoxide hydrolase (sEH) have been identified, many of which have altered functional activity in vitro. We performed a case-control study to determine the prevalence of epoxygenase-related SNP in African American individuals and to evaluate whether these SNP are associated with increased risk of hypertension. METHODS: Normotensive African American individuals (N = 107) and African American patients with hypertension (N = 108) were recruited. DNA was extracted from a venous blood sample and genotyped for CYP2C8*2,*3, CYP2C9*2-*5,*8,*11, CYP2J2 *2-*7, L50L, R49S, V113M, N124S, sEH R287Q, and sEH 403Rins variant alleles by allelic discrimination using real-time polymerase chain reaction. Genotype and allele frequencies were calculated and associations with hypertension were estimated using unconditional logistic regression, adjusting for age and sex. RESULTS: No association was found between any of the variant alleles and hypertension. We did find that only the CYP2C8*3and CYP2C9*2 alleles were in strong linkage disequilibrium in both the hypertensive and healthy African American groups, a finding that was reported previously in healthy individuals of white ethnicity. CONCLUSIONS: These results suggest that these epoxygenase-related SNP are not associated with increased risk of hypertension in the African American population. There was significant linkage disequilibrium between CYP2C8*3 and CYP2C9*2 alleles that was not associated with hypertension.
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Negro o Afroamericano/genética , Sistema Enzimático del Citocromo P-450/genética , Epóxido Hidrolasas/genética , Hipertensión/genética , Polimorfismo de Nucleótido Simple/genética , Adulto , Alelos , Hidrocarburo de Aril Hidroxilasas/genética , Estudios de Casos y Controles , Citocromo P-450 CYP2C8 , Citocromo P-450 CYP2C9 , Citocromo P-450 CYP2J2 , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Hipertensión/enzimología , Hipertensión/etnología , Desequilibrio de Ligamiento , Louisiana/epidemiología , Masculino , Persona de Mediana Edad , Oxigenasas/genética , Prevalencia , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
There is abundant evidence that chronic renal failure (CRF) and end-stage renal disease (ESRD) alter drug disposition by affecting protein and tissue binding and reducing systemic clearance of renally cleared drugs. What is not fully appreciated is that CRF can significantly reduce nonrenal clearance and alter the bioavailability of drugs predominantly metabolized by the liver. Animal studies in CRF have shown a major down-regulation (40-85%) of hepatic cytochrome P-450 metabolism involving specific isozymes. Phase II reactions such as acetylation and glucuronidation are also involved, with some isozymes showing induction and others inhibition. Hepatic enzymes exhibiting genetic polymorphisms such as N-acetyl-transferase-2 (NAT-2), which is responsible for the rapid and slow acetylator phenotypes, have been shown to be inhibited by ESRD and reversed by transplantation. There is some evidence pointing to the possibility of inhibitory factors circulating in the serum in ESRD patients which may be dialyzable. This review includes all significant animal and clinical studies using the search terms "chronic renal failure,""cytochrome P-450," and "liver metabolism" over the past 10 years obtained from the National Library of Medicine MEDLINE database, including relevant articles back to 1969.
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Fallo Renal Crónico/metabolismo , Hígado/metabolismo , Preparaciones Farmacéuticas/metabolismo , Animales , Sistema Enzimático del Citocromo P-450/metabolismo , Humanos , Inactivación Metabólica/fisiología , Fallo Renal Crónico/fisiopatología , Hígado/fisiopatología , Tasa de Depuración Metabólica/fisiología , Modelos Biológicos , RatasRESUMEN
PURPOSE: Cancer is, unfortunately, often a terminal disease. The goal of therapy for many patients with cancer is palliation of symptoms common at the end of life, including pain, depression, and cognitive dysfunction. Methylphenidate is a psychostimulant most commonly used in the treatment of attention deficit hyperactivity disorder. In this report, we review the use of methylphenidate in the palliative care of patients with cancer. METHODS: This review was written on the basis of a computerized literature search of Medline. We considered all English language publications from 1966 to present using the following key words: methylphenidate, palliative care, and cancer. Forty-nine articles were identified as being relevant for this review. RESULTS: On the basis of this review, we came to the conclusion that methylphenidate is used to ameliorate opioid-induced somnolence, to augment the analgesic effects of opioids, to treat depression, and to improve cognitive function in patients with cancer. CONCLUSION: The medical literature supports the palliative use of methylphenidate in the care of patients with cancer. Further placebo-controlled trials are needed to elucidate the precise role that methylphenidate will have in providing symptom relief to dying patients.