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1.
Artigo em Inglês | MEDLINE | ID: mdl-31548185

RESUMO

Doxycycline is a tetracycline-class antimicrobial labeled by the United States (U.S.) Food and Drug Administration for children >8 years of age for many common childhood infections. Doxycycline is not labeled for children ≤8 years of age, due to the association between tetracycline class antibiotics and tooth staining, although doxycycline may be used off-label in severe conditions. Accordingly, there is a paucity of pharmacokinetic (PK) data to guide dosing in children 8 years and younger. We leveraged opportunistically-collected plasma samples after intravenous (IV) and oral doxycycline doses received per standard of care to characterize the PK of doxycycline in children of different ages, and evaluated the effect of obesity and fasting status on PK parameters.We developed a population PK model of doxycycline using data collected from 47 patients 0-18 years of age, including 14 participants ≤8 years. We developed a 1 compartment PK model and found doxycycline clearance to be 3.32 L/h/70 kg and volume to be 96.8 L/70kg for all patients; comparable to values reported in adults. We estimated a bioavailability of 89.6%, also consistent with adult data. Allometrically scaled clearance and volume of distribution did not differ between children 2 to ≤8 years of age and children >8 to ≤18 years of age, suggesting that younger children may be given the same per kg dosing. Obese and fasting status were not selected for inclusion in the final model. Additional doxycycline PK samples collected in future studies may be used to improve model performance and maximize its clinical value.

2.
J Clin Pharmacol ; 59(12): 1606-1619, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31317556

RESUMO

Milrinone is a type 3 phosphodiesterase inhibitor used to improve cardiac output in critically ill infants and children. Milrinone is primarily excreted unchanged in the urine, raising concerns for toxic accumulation in the setting of renal dysfunction of critical illness. We developed a population pharmacokinetic model of milrinone using nonlinear mixed-effects modeling in NONMEM to perform dose-exposure simulations in children with variable renal function. We included children aged <21 years who received intravenous milrinone per clinical care. Plasma milrinone concentrations were measured using a validated liquid chromatography-tandem mass spectrometry assay (range 1-5000 ng/mL). We performed dose-exposure simulations targeting steady-state therapeutic concentrations of 100-300 ng/mL previously established in adults and children with cardiac dysfunction. We simulated concentrations over 48 hours in typical subjects with decreasing creatinine clearance (CrCl), estimated using the updated bedside Schwartz equation. Seventy-four patients contributed 111 plasma samples (concentration range, 4-634 ng/mL). The median (range) postmenstrual age (PMA) was 3.7 years (0-18), and median weight (WT) was 13.1 kg (2.6-157.7). The median serum creatinine and CrCl were 0.5 mg/dL (0.1-3.1) and 117.2 mL/min/1.73 m2 (13.1-261.3), respectively. A 1-compartment model characterized the pharmacokinetic data well. The final model parameterization was: Clearance (L/h) = 15.9*(WT [kg] / 70)0.75 * (PMA1.12 / (67.71.12 +PMA1.12 )*(CrCl / 117)0.522 ; and Volume of Distribution (L) = 32.2*(WT [kg] / 70). A loading dose of 50 µg/kg followed by a continuous infusion of 0.5 µg/kg/min resulted in therapeutic concentrations, except when CrCl was severely impaired at ≤30 mL/min/1.73 m2 . In this setting, a 25 µg/kg loading dose and 0.25 µg/kg/min continuous infusion resulted in therapeutic exposures.

3.
Urol Oncol ; 2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30879969

RESUMO

Prostate cancer (PCa) is the most common cancer among men. Advances in early detection and successful treatments have improved cancer-specific survival. With prolonged survival, PCa patients now suffer from the effects of aging and are at increasing risk for the development of cardiovascular (CV) risk factors and CV disease. Androgen deprivation therapy (ADT) is the mainstay treatment of advanced PCa. There is conflicting evidence about whether or not ADT is associated with increased CV morbidity and mortality. Metabolic abnormalities such as increasing body weight, reduced insulin sensitivity, dyslipidemia, and activation of T cells to the Th1 phenotype, resulting in atherosclerotic plaque destabilization, have been proposed as possible mechanisms by which ADT may increase the risk of CV events. Type of ADT and preexisting CV history also seem to play a major role in the risk of subsequent CV events. Ongoing prospective clinical trials will help define whether there is any difference between gonadotropin-releasing hormone agonists and antagonists in terms of CV morbidity and mortality.

5.
Circulation ; 139(7): 863-873, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30586739

RESUMO

BACKGROUND: Modern cardiometabolic clinical trials often include cardiovascular death as a component of a composite primary outcome, requiring central adjudication by a clinical events committee to classify cause of death. However, sometimes the cause of death cannot be determined from available data. The US Food and Drug Administration has indicated that this circumstance should occur only rarely, but its prevalence has not been formally assessed. METHODS: Data from 9 global clinical trials (2009-2017) with long-term follow-up and blinded, centrally adjudicated cause of death were used to calculate the proportion of deaths attributed to cardiovascular, noncardiovascular, or undetermined causes by therapeutic area (diabetes mellitus/pre-diabetes mellitus, stable atherosclerosis, atrial fibrillation, and acute coronary syndrome), region of patient enrollment, and year of trial manuscript publication. Patient- and trial-level variables associated with undetermined cause of death were identified using a logistic model. RESULTS: Across 127 049 enrolled participants from 9 trials, there were 9259 centrally adjudicated deaths: 5012 (54.1%) attributable to cardiovascular causes, 2800 (30.2%) attributable to noncardiovascular causes, and 1447 (15.6%) attributable to undetermined causes. There was variability in the proportion of deaths ascribed to undetermined causes by trial therapeutic area, region of enrollment, and year of trial manuscript publication. On multivariable analysis, acute coronary syndrome or atrial fibrillation trial (versus atherosclerotic vascular disease or diabetes mellitus/pre-diabetes mellitus), longer time from enrollment to death, more recent trial manuscript publication year, enrollment in North America (versus Western Europe), female sex, and older age were associated with greater likelihood of death of undetermined cause. CONCLUSIONS: In 9 cardiometabolic clinical trials with long-term follow-up, approximately 16% of deaths had undetermined causes. This provides a baseline for quality assessment of clinical trials and informs operational efforts to potentially reduce the frequency of undetermined deaths in future clinical research.

6.
J Am Heart Assoc ; 7(24): e009609, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30526198

RESUMO

Background Vorapaxar, a protease-activated receptor-1 antagonist, is approved for secondary prevention of cardiovascular events but is associated with increased intracranial hemorrhage. Methods and Results TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) was a trial of vorapaxar versus placebo among patients with acute coronary syndrome. Strokes were adjudicated by a central events committee. Of 12 944 patients, 199 (1.5%) had ≥1 stroke during the study period (median follow-up, 477 days). Four patients had a single stroke of unknown type; 195 patients had ≥1 stroke classified as hemorrhagic or nonhemorrhagic (165 nonhemorrhagic, 28 hemorrhagic, and 2 both). Strokes occurred in 96 of 6473 patients (1.5%) assigned vorapaxar and 103 of 6471 patients (1.6%) assigned placebo. Kaplan-Meier incidence of stroke for vorapaxar versus placebo was higher for hemorrhagic stroke (0.45% versus 0.14% [hazard ratio, 2.74; 95% confidence interval, 1.22-6.15]), lower but not significantly different for nonhemorrhagic stroke (1.53% versus 1.98% at 2 years [hazard ratio, 0.79; 95% confidence interval, 0.58-1.07]), and similar for stroke overall (1.93% versus 2.13% at 2 years [hazard ratio, 0.94; 95% confidence interval, 0.71-1.24]). Conclusions Stroke occurred in <2% of patients. Vorapaxar-assigned patients had increased hemorrhagic stroke but a nonsignificant trend toward lower nonhemorrhagic stroke. Overall stroke frequency was similar with vorapaxar versus placebo.

7.
J Am Coll Cardiol ; 72(16): 1923-1925, 2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30309469
8.
Artigo em Inglês | MEDLINE | ID: mdl-30219887

RESUMO

Aims: The management of anticoagulation therapy in patients with atrial fibrillation (AF) and cancer is challenging due to increased thrombotic and bleeding risks. We sought to determine the safety and efficacy of rivaroxaban in patients with AF and a history of cancer. Methods and Results: ROCKET AF randomized 14,264 patients with AF to rivaroxaban or warfarin with a median follow-up of 1.9 years. Cox regression models were used to assess the association between cancer history and clinical outcomes, and the relative treatment effect of rivaroxaban versus warfarin in these patients. A total of 640 patients enrolled in ROCKET AF had a history of cancer, with the most common types being prostate (28.6%), colorectal (16.1%), and breast (14.7%) cancer. Patients with a history of cancer were older, more frequently male, more likely to have prior VKA use, and had higher rates of overall bleeding (HR 1.30 95% CI 1.16-1.47; p < 0.0001) and non-cardiovascular death (HR 1.47 95% CI 1.04-2.07; p = 0.031) compared with those with no cancer history. There were no significant associations between cancer history and stroke, venous thromboembolism, or myocardial infarction. The relative efficacy of rivaroxaban versus warfarin for prevention of stroke/systemic embolism was similar in those with and without a history of cancer (interaction p-value=0.21). Conclusion: In ROCKET AF, a history of cancer was associated with a higher risk of bleeding and non-cardiovascular death, but not ischemic events. The relative efficacy and safety of rivaroxaban compared with warfarin were not significantly different in patients with and without a history of cancer. The results of this study are exploratory and should be taken in context of the study population, which may not be generalizable to those with advanced malignancy. Further investigation is needed to understand optimal anticoagulation strategies in patients with AF and cancer.

9.
J Clin Pharmacol ; 2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29677389

RESUMO

Ketamine is an N-methyl D-aspartate receptor antagonist used off-label to facilitate dissociative anesthesia in children undergoing invasive procedures. Available for both intravenous and intramuscular administration, ketamine is commonly used when vascular access is limited. Pharmacokinetic (PK) data in children are sparse, and the bioavailability of intramuscular ketamine in children is unknown. We performed 2 prospective PK studies of ketamine in children receiving either intramuscular or intravenous ketamine and combined the data to develop a pediatric population PK model using nonlinear mixed-effects methods. We applied our model by performing dosing simulations targeting plasma concentrations previously associated with analgesia (>100 ng/mL) and anesthesia awakening (750 ng/mL). A total of 113 children (50 intramuscular and 63 intravenous ketamine) with a median age of 3.3 years (range 0.02 to 17.6 years), and median weight of 14 kg (2.4 to 176.1) contributed 275 plasma samples (149 after intramuscular, 126 after intravenous ketamine). A 2-compartment model with first-order absorption following intramuscular administration and first-order elimination described the data best. Allometrically scaled weight was included in the base model for central and peripheral volume of distribution (exponent 1) and for clearance and intercompartmental clearance (exponent 0.75). Model-estimated bioavailability of intramuscular ketamine was 41%. Dosing simulations suggest that doses of 2 mg/kg intravenously and 8 mg/kg or 6 mg/kg intramuscularly, depending on age, provide adequate sedation (plasma ketamine concentrations >750 ng/mL) for procedures lasting up to 20 minutes.

10.
J Pharmacokinet Pharmacodyn ; 45(3): 419-430, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29435949

RESUMO

Amiodarone is a first-line antiarrhythmic for life-threatening ventricular fibrillation or ventricular tachycardia in children, yet little is known about its pharmacokinetics (PK) in this population. We developed a population PK (PopPK) model using samples collected via an opportunistic study design of children receiving amiodarone per standard of care supplemented by amiodarone PK data from the literature. Both study data and literature data were predominantly from infants < 2 years old, so our analysis was restricted to this group. The final combined dataset consisted of 266 plasma drug concentrations in 45 subjects with a median (interquartile range) postnatal age of 40.1 (11.0-120.4) days and weight of 3.9 (3.1-5.1) kg. Since the median sampling time after the first dose was short (study: 95 h; literature: 72 h) relative to the terminal half-life estimated in adult PopPK studies, values of the deep compartment volume and flow were fixed to literature values. A 3-compartment model best described the data and was validated by visual predictive checks and non-parametric bootstrap analysis. The final model included body weight as a covariate on all volumes and on both inter-compartmental and elimination clearances. The empiric Bayesian estimates for clearance (CL), volume of distribution at steady state, and terminal half-life were 0.25 (90% CL 0.14-0.36) L/kg/h, 93 (68-174) L/kg, and 266 (197-477) h, respectively. These studies will provide useful information for future PopPK studies of amiodarone in infants and children that could improve dosage regimens.

11.
Ther Drug Monit ; 40(1): 103-108, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29271816

RESUMO

BACKGROUND: Dried blood spot (DBS) is a practical sampling strategy for pharmacokinetic studies in neonates. The utility of DBS to determine the population pharmacokinetics (pop-PK) of ampicillin, as well as accuracy versus plasma samples, was evaluated. METHODS: An open-label, multicenter, opportunistic, prospective study was conducted in neonates. Ampicillin concentrations from plasma and DBS (CONCPlasma and CONCDBS) were measured by liquid chromatographic tandem mass spectrometry and analyzed using pop-PK and statistical (including transformation) approaches. RESULTS: A total of 29 paired plasma and DBS samples from 18 neonates were analyzed. The median (range) gestational age and postnatal age were 37 (27-41) weeks and 8 (1-26) days, respectively. The geometric mean of CONCDBS to CONCPlasma ratio was 0.56. Correlation analysis demonstrated strong association between CONCPlasma and CONCDBS (r = 0.902, analysis of variance P < 0.001). Using linear regression transformation, the estimated CONCPlasma (eCONCPlasma) was derived using (CONCDBS - 3.223)/0.51. The median bias and geometric mean ratio improved to -11% and 0.88 (Wilcoxon signed-rank test, P < 0.001), respectively, when comparing eCONCPlasma to CONCPlasma. Furthermore, using pop-PK modeling, the median bias (interquartile range) for clearance and individual predicted concentrations improved to 8% (-11 to 50) and -8% (-34 to 11), respectively, when eCONCPlasma was used. CONCLUSIONS: After transformation, DBS sampling accurately predicted ampicillin exposure in neonates.


Assuntos
Ampicilina/farmacocinética , Teste em Amostras de Sangue Seco/métodos , Ampicilina/sangue , Cromatografia Líquida , Feminino , Humanos , Recém-Nascido , Masculino , Modelos Biológicos , Estudos Prospectivos , Espectrometria de Massas em Tandem
12.
Artigo em Inglês | MEDLINE | ID: mdl-29084742

RESUMO

Trimethoprim (TMP)-sulfamethoxazole (SMX) is used to treat various types of infections, including community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and Pneumocystis jirovecii infections in children. Pharmacokinetic (PK) data for infants and children are limited, and the optimal dosing is not known. We performed a multicenter, prospective PK study of TMP-SMX in infants and children. Separate population PK models were developed for TMP and SMX administered by the enteral route using nonlinear mixed-effects modeling. Optimal dosing was determined on the basis of the matching adult TMP exposure and attainment of the surrogate pharmacodynamic (PD) target for efficacy, a free TMP concentration above the MIC over 50% of the dosing interval. Data for a total of 153 subjects (240 samples for PK analysis) with a median postnatal age of 8 years (range, 0.1 to 20 years) contributed to the analysis for both drugs. A one-compartment model with first-order absorption and elimination characterized the TMP and SMX PK data well. Weight was included in the base model for clearance (CL/F) and volume of distribution (V/F). Both TMP and SMX CL/F increased with age. In addition, TMP and SMX CL/F were inversely related to the serum creatinine and albumin concentrations, respectively. The exposure achieved in children after oral administration of TMP-SMX at 8/40 mg/kg of body weight/day divided into administration every 12 h matched the exposure achieved in adults after administration of TMP-SMX at 320/1,600 mg/day divided into administration every 12 h and achieved the PD target for bacteria with an MIC of 0.5 mg/liter in >90% of infants and children. The exposure achieved in children after oral administration of TMP-SMX at 12/60 and 15/75 mg/kg/day divided into administration every 12 h matched the exposure achieved in adults after administration of TMP-SMX at 640/3,200 mg/day divided into administration every 12 h in subjects 6 to <21 years and 0 to <6 years of age, respectively, and was optimal for bacteria with an MIC of up to 1 mg/liter.

13.
Ann Dyslexia ; 67(3): 401-426, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29134481

RESUMO

In this study, we present the results of an original experimental protocol designed to assess the performance in a pluralization task of 52 Italian children divided into two groups: 24 children with developmental dyslexia (mean age 10.0 years old) and 28 typically developing children (mean age 9.11 years old). Our task, inspired by Berko's Wug Test, had the aim of testing the subjects' ability to apply pluralization rules to nonwords in the morphologically complex context of Italian nominal inflection. Results demonstrate that dyslexics display poorer morphological skills in comparison to controls, showing lower accuracy in the task. Furthermore, the dissimilar performances reported by the subjects in the different conditions indicate that the ability to inflect nonwords depends on factors such as the rule's productivity, frequency, and opacity with respect to gender. Finally, the children's performance in this task was significantly related to their reading proficiency, and it could predict accuracy in word reading independently of phonological awareness and working memory.


Assuntos
Dislexia/diagnóstico , Dislexia/epidemiologia , Testes de Linguagem , Fonética , Leitura , Adolescente , Conscientização/fisiologia , Criança , Feminino , Humanos , Itália/epidemiologia , Linguística/métodos , Masculino , Memória de Curto Prazo/fisiologia
14.
Eur Heart J Qual Care Clin Outcomes ; 3(3): 192-197, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28838088

RESUMO

Aims: The presence of cancer can complicate treatment choices for patients with atrial fibrillation (AF) increasing both the risk of thrombotic and bleeding events. Methods and results: Using data from Outcomes Registry for Better Informed Treatment of Atrial Fibrillation, we aimed to characterize AF patients with cancer, to describe their management and to assess the association between cancer and cardiovascular (CV) outcomes. Among 9749 patients, 23.8% had history of cancer (57% solid malignancy, 1.3% leukaemia, 3.3% lymphoma, 40% other type, and 2.2% metastatic cancer). Patients with history of cancer were older, more likely to have CV disease, CV risk factors, and prior gastrointestinal bleeding. No difference in antiarrhythmic and antithrombotic therapy was observed between those with and without cancer. Patients with history of cancer had a significantly higher risk of death (7.8 vs. 4.9 deaths per 100 patient-years follow-up, P = 0.0003) mainly driven by non-CV death (4.2 vs. 2.4 per 100 patient-years follow-up; P = 0.0004) and higher risk of major bleeding (5.1 vs. 3.5 per 100 patient-years follow-up; P = 0.02) compared with non-cancer patients; no differences were observed in risks of strokes/non-central nervous system embolism (1.96 vs. 1.48, P = 0.74) and CV death (2.89 vs. 2.07, P = 0.35) between the two groups. Conclusion: A history of cancer is common among AF patients with up to one in four patients having both. Antithrombotic therapy, rates of cerebrovascular accident, other thrombotic events and cardiac death were similar in AF patients with or without a history of cancer. Patients with cancer, however, were at higher risk of major bleeding and non-CV death.


Assuntos
Anticoagulantes/administração & dosagem , Fibrilação Atrial/terapia , Hemorragia/epidemiologia , Neoplasias/complicações , Medição de Risco , Acidente Vascular Cerebral/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Fibrilação Atrial/complicações , Relação Dose-Resposta a Droga , Feminino , Hemorragia/induzido quimicamente , Humanos , Incidência , Masculino , Neoplasias/epidemiologia , Sistema de Registros , Fatores de Risco , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Taxa de Sobrevida/tendências , Estados Unidos/epidemiologia
15.
Am J Med ; 130(12): 1440-1448.e1, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28739198

RESUMO

BACKGROUND: Cancer is associated with a prothrombotic state and increases the risk of thrombotic events in patients with atrial fibrillation. We described the clinical characteristics and outcomes and assessed the safety and efficacy of apixaban versus warfarin in patients with atrial fibrillation and cancer in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial. METHODS: The association between cancer and clinical outcomes was assessed using Cox regression models. At baseline, 1236 patients (6.8%) had a history of cancer; 12.7% had active cancer, and 87.3% had remote cancer. RESULTS: There were no significant associations between history of cancer and stroke/systemic embolism, major bleeding, or death. The effect of apixaban versus warfarin for the prevention of stroke/systemic embolism was consistent among patients with a history of cancer (event/100 patient-years = 1.4 vs 1.2; hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.53-2.26) and no cancer (1.3 vs 1.6; HR, 0.77; 95% CI, 0.64-0.93) (P interaction = .37). The safety and efficacy of apixaban versus warfarin were preserved among patients with and without active cancer. Apixaban was associated with a greater benefit for the composite of stroke/systemic embolism, myocardial infarction, and death in active cancer (HR, 0.30; 95% CI, 0.11-0.83) versus without cancer (HR, 0.86; 95% CI, 0.78-0.95), but not in remote cancer (HR, 1.46; 95% CI, 1.01-2.10) (interaction P = .0028). CONCLUSIONS: Cancer was not associated with a higher risk of stroke. The superior efficacy and safety of apixaban versus warfarin were consistent in patients with and without cancer. Our positive findings regarding apixaban use in patients with atrial fibrillation and cancer are exploratory and promising, but warrant further evaluation.


Assuntos
Anticoagulantes/uso terapêutico , Inibidores do Fator Xa/uso terapêutico , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Acidente Vascular Cerebral/prevenção & controle , Tromboembolia/prevenção & controle , Varfarina/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Acidente Vascular Cerebral/etiologia , Tromboembolia/etiologia , Resultado do Tratamento
16.
Ther Drug Monit ; 39(1): 13-20, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28081041

RESUMO

BACKGROUND: Drugs that exhibit close margins between therapeutic and toxic blood concentrations are considered to have a narrow therapeutic index (NTI). The Food and Drug Administration has proposed that NTI drugs should have more stringent bioequivalence standards for approval of generic formulations. However, many immunosuppressant drugs do not have a well-defined therapeutic index (TI). METHODS: We sought to determine whether safety, efficacy, and pharmacokinetic data obtained from the medical literature through a comprehensive literature search could be used to estimate the TI of cyclosporine, tacrolimus, and sirolimus. In this analysis, we considered TI ≤2 as a criterion to define a drug as having an NTI. RESULTS: Published literature indicates that cyclosporine has a TI of 2-3, which falls just short of our criteria to be classified as having an NTI. We found sirolimus and tacrolimus to have a therapeutic range of 5-12 ng/mL and of 5-20 ng/mL, respectively, but were unable to calculate the TI. CONCLUSIONS: Although the current literature does not provide a clear indication that these drugs have an NTI, the routine use of therapeutic drug monitoring in clinical practice suggests that more stringent testing of their pharmacokinetic and pharmacodynamic properties should be performed before the approval of generic formulations.


Assuntos
Imunossupressores/administração & dosagem , Transplante de Rim/métodos , Índice Terapêutico , Ciclosporina/administração & dosagem , Ciclosporina/efeitos adversos , Ciclosporina/farmacocinética , Monitoramento de Medicamentos/métodos , Medicamentos Genéricos/administração & dosagem , Medicamentos Genéricos/efeitos adversos , Medicamentos Genéricos/farmacocinética , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/farmacocinética , Sirolimo/administração & dosagem , Sirolimo/efeitos adversos , Sirolimo/farmacocinética , Tacrolimo/administração & dosagem , Tacrolimo/efeitos adversos , Tacrolimo/farmacocinética , Equivalência Terapêutica
17.
Minerva Endocrinol ; 42(3): 228-237, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27808485

RESUMO

INTRODUCTION: The aim of this review is to discuss the consequences of potential pharmacokinetic interactions between proton pump inhibitors (PPIs) and antiplatelet therapy on cardiovascular (CV) outcomes and provide guidance on the management of concomitant use of PPIs in patients on dual antiplatelet therapy (DAPT). EVIDENCE ACQUISITION: DAPT combining aspirin and oral P2Y12 receptor inhibitors increases the risk of gastrointestinal (GI) bleeding, with higher rates of morbidity and mortality in patients undergoing percutaneous coronary intervention (PCI). PPIs are recommended in patients at risk of bleeding to reduce the risk of GI hemorrhage. PPIs can reduce the metabolism of clopidogrel by competing with CYP450 enzymes, mostly CYP2C19 isoform. The clinical significance of this pharmacological interaction is not uniform in observational studies. The only randomized clinical trial assessing the clinical relevance of clopidogrel-omeprazole interaction showed that the use of omeprazole was associated with a reduction in GI bleeding, without any differences in CV outcomes. EVIDENCE SYNTHESIS: Several systematic reviews and meta-analyses suggest an increased risk of major adverse cardiovascular events (MACE), but not of mortality in patients with concomitant use of PPIs and clopidogrel. Two meta-analysis studying the interactions between individual PPIs and clopidogrel failed to demonstrate any strong relationships with adverse CV outcomes. CONCLUSIONS: PPIs should be administered in patients on DAPT at risk for GI bleeding. However the uncertain benefit of PPIs in patients who are not at risk of GI bleeding and the unclear risk in MACE suggest that caution should be used when prescribing PPIs in these patients.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Inibidores da Agregação de Plaquetas/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Quimioterapia Combinada , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/prevenção & controle , Humanos , Inibidores da Agregação de Plaquetas/efeitos adversos , Resultado do Tratamento
18.
Ther Drug Monit ; 38(6): 728-737, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27764025

RESUMO

BACKGROUND: Defining a drug's therapeutic index (TI) is important for patient safety and regulating the development of generic drugs. For many drugs, the TI is unknown. A systematic approach was developed to characterize the TI of a drug using therapeutic drug monitoring and electronic health record (EHR) data with pharmacokinetic (PK) modeling. This approach was first tested on phenytoin, which has a known TI, and then applied to lamotrigine, which lacks a defined TI. METHODS: Retrospective EHR data from patients in a tertiary hospital were used to develop phenytoin and lamotrigine population PK models and to identify adverse events (anemia, thrombocytopenia, and leukopenia) and efficacy outcomes (seizure-free). Phenytoin and lamotrigine concentrations were simulated for each day with an adverse event or seizure. Relationships between simulated concentrations and adverse events and efficacy outcomes were used to calculate the TI for phenytoin and lamotrigine. RESULTS: For phenytoin, 93 patients with 270 total and 174 free concentrations were identified. A de novo 1-compartment PK model with Michaelis-Menten kinetics described the data well. Simulated average total and free concentrations of 10-15 and 1.0-1.5 mcg/mL were associated with both adverse events and efficacy in 50% of patients, resulting in a TI of 0.7-1.5. For lamotrigine, 45 patients with 53 concentrations were identified. A published 1-compartment model was adapted to characterize the PK data. No relationships between simulated lamotrigine concentrations and safety or efficacy endpoints were seen; therefore, the TI could not be calculated. CONCLUSIONS: This approach correctly determined the TI of phenytoin but was unable to determine the TI of lamotrigine due to a limited sample size. The use of therapeutic drug monitoring and EHR data to aid in narrow TI drug classification is promising, but it requires an adequate sample size and accurate characterization of concentration-response relationships.


Assuntos
Anticonvulsivantes/farmacocinética , Anticonvulsivantes/uso terapêutico , Fenitoína/farmacocinética , Fenitoína/uso terapêutico , Triazinas/farmacocinética , Triazinas/uso terapêutico , Adulto , Idoso , Monitoramento de Medicamentos/métodos , Medicamentos Genéricos/farmacocinética , Medicamentos Genéricos/uso terapêutico , Registros Eletrônicos de Saúde , Feminino , Humanos , Lamotrigina , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice Terapêutico
19.
Clin Neuropharmacol ; 39(5): 232-40, 2016 Sep-Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27428884

RESUMO

OBJECTIVES: Our study aimed to determine whether data obtained from the medical literature can be used to estimate the therapeutic index of 5 antiepileptic drugs (AEDs): carbamazepine, lamotrigine, phenobarbital, phenytoin, and valproate. METHODS: We performed a literature search using PubMed and EMBASE to collect published safety, efficacy, and therapeutic monitoring data for 5 AEDs and extracted all relevant information into a drug- and study-specific drug database. For each AED, we summarized (1) type, severity, and incidence of toxicity-related adverse events and toxicity-associated range of drug doses or concentrations; (2) effective versus toxic concentration and dose (therapeutic range); and (3) therapeutic drug monitoring practices. We defined therapeutic index as the ratio of the minimum toxic concentration to the minimum effective concentration. RESULTS: We reviewed a total of 810 full-text articles and extracted data from 163. The literature suggests that the therapeutic index of phenytoin is 2. The therapeutic indices of phenobarbital and valproate exceed 2. There were insufficient data to precisely quantify the therapeutic indices of carbamazepine and lamotrigine. CONCLUSIONS: For some drugs, this approach offers a low-cost method of therapeutic index estimation. Our results can serve as preliminary data for future trials and as guidance for US Food and Drug Administration decision making regarding narrow therapeutic index classification.


Assuntos
Anticonvulsivantes/uso terapêutico , Monitoramento de Medicamentos/métodos , Epilepsia/tratamento farmacológico , Resultado do Tratamento , Bases de Dados Bibliográficas/estatística & dados numéricos , Humanos
20.
Ther Drug Monit ; 38(5): 600-6, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27259059

RESUMO

BACKGROUND: Sirolimus, an immunosuppressive agent used in renal transplantation, can prevent allograft rejection. Identification of the therapeutic index (the ratio of minimum toxic concentration to minimum therapeutic concentration) for immunosuppresants is necessary to optimize the care of patients and set standards for bioequivalence evaluation of sirolimus products. However, the therapeutic index for sirolimus has been inconsistently defined, potentially because of inconsistencies in sirolimus exposure-response relationships. METHODS: The authors used retrospective therapeutic drug monitoring data from the electronic health records of patients treated in a tertiary health care system from 2008 to 2014 to (1) develop a population pharmacokinetic (PK) model, (2) use the model to simulate sirolimus concentrations, and (3) characterize the exposure-response relationship. Using Wilcoxon rank-sum and Fisher exact tests, the authors determined relationships between sirolimus exposure and adverse events (AEs) (anemia, leukopenia, thrombocytopenia, hyperlipidemia, and decline in renal function) and the composite efficacy end point of graft loss or rejection. RESULTS: The developed 2-compartment population PK model showed appropriate goodness of fit. In a late-phase (>12 months), postrenal transplant population of 27 inpatients, the authors identified statistically significant relationships between 83 simulated peak and trough sirolimus concentrations and outcomes: graft loss or rejection (P = 0.018) and decline in renal function (P = 0.006), respectively. CONCLUSIONS: Use of therapeutic drug monitoring results and PK modeling permitted correlation of sirolimus concentrations with graft loss or rejection and decline in renal function. However, the method was limited in its assessment of other AEs. To better evaluate sirolimus exposure-response relationships, the method should be applied to a larger sample of newly transplanted patients with a higher propensity toward AEs or efficacy failure.


Assuntos
Monitoramento de Medicamentos , Registros Eletrônicos de Saúde , Transplante de Rim , Modelos Biológicos , Sirolimo/farmacocinética , Adulto , Idoso , Feminino , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/farmacocinética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sirolimo/efeitos adversos , Sirolimo/sangue
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