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1.
N Engl J Med ; 378(7): 603-614, 2018 02 15.
Article in English | MEDLINE | ID: mdl-29130810

ABSTRACT

BACKGROUND: Intravenous sodium bicarbonate and oral acetylcysteine are widely used to prevent acute kidney injury and associated adverse outcomes after angiography without definitive evidence of their efficacy. METHODS: Using a 2-by-2 factorial design, we randomly assigned 5177 patients at high risk for renal complications who were scheduled for angiography to receive intravenous 1.26% sodium bicarbonate or intravenous 0.9% sodium chloride and 5 days of oral acetylcysteine or oral placebo; of these patients, 4993 were included in the modified intention-to-treat analysis. The primary end point was a composite of death, the need for dialysis, or a persistent increase of at least 50% from baseline in the serum creatinine level at 90 days. Contrast-associated acute kidney injury was a secondary end point. RESULTS: The sponsor stopped the trial after a prespecified interim analysis. There was no interaction between sodium bicarbonate and acetylcysteine with respect to the primary end point (P=0.33). The primary end point occurred in 110 of 2511 patients (4.4%) in the sodium bicarbonate group as compared with 116 of 2482 (4.7%) in the sodium chloride group (odds ratio, 0.93; 95% confidence interval [CI], 0.72 to 1.22; P=0.62) and in 114 of 2495 patients (4.6%) in the acetylcysteine group as compared with 112 of 2498 (4.5%) in the placebo group (odds ratio, 1.02; 95% CI, 0.78 to 1.33; P=0.88). There were no significant between-group differences in the rates of contrast-associated acute kidney injury. CONCLUSIONS: Among patients at high risk for renal complications who were undergoing angiography, there was no benefit of intravenous sodium bicarbonate over intravenous sodium chloride or of oral acetylcysteine over placebo for the prevention of death, need for dialysis, or persistent decline in kidney function at 90 days or for the prevention of contrast-associated acute kidney injury. (Funded by the U.S. Department of Veterans Affairs Office of Research and Development and the National Health and Medical Research Council of Australia; PRESERVE ClinicalTrials.gov number, NCT01467466 .).


Subject(s)
Acetylcysteine/therapeutic use , Acute Kidney Injury/prevention & control , Angiography , Contrast Media/adverse effects , Sodium Bicarbonate/therapeutic use , Sodium Chloride/therapeutic use , Acute Kidney Injury/chemically induced , Administration, Oral , Aged , Angiography/adverse effects , Creatinine/blood , Double-Blind Method , Female , Fluid Therapy , Humans , Infusions, Intravenous , Male , Middle Aged , Renal Dialysis , Renal Insufficiency, Chronic/therapy , Risk Factors , Treatment Outcome
2.
Lancet ; 391(10134): 1997-2007, 2018 05 19.
Article in English | MEDLINE | ID: mdl-29759512

ABSTRACT

BACKGROUND: Few studies have examined the efficacy of drug-eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure compared with bare-metal stents (BMS) in patients undergoing stenting of de-novo SVG lesions. We assessed the risks and benefits of the use of DES versus BMS in de-novo SVG lesions. METHODS: Patients were recruited to our double-blind, randomised controlled trial from 25 US Department of Veterans Affairs centres. Eligible participants were aged at least 18 years and had at least one significant de-novo SVG lesion (50-99% stenosis of a 2·25-4·5 mm diameter SVG) requiring percutaneous coronary intervention with intent to use embolic protection devices. Enrolled patients were randomly assigned, in a 1:1 ratio, by phone randomisation system to receive a DES or BMS. Randomisation was stratified by presence or absence of diabetes and number of target SVG lesions requiring percutaneous coronary intervention (one or two or more) within each participating site by use of an adaptive scheme intended to balance the two stent type groups on marginal totals for the stratification factors. Patients, referring physicians, study coordinators, and outcome assessors were masked to group allocation. The primary endpoint was the 12-month incidence of target vessel failure, defined as the composite of cardiac death, target vessel myocardial infarction, or target vessel revascularisation. The DIVA trial is registered with ClinicalTrials.gov, number NCT01121224. FINDINGS: Between Jan 1, 2012, and Dec 31, 2015, 599 patients were randomly assigned to the stent groups, and the data for 597 patients were used. The patients' mean age was 68·6 (SD 7·6) years, and 595 (>99%) patients were men. The two stent groups were similar for most baseline characteristics. At 12 months, the incidence of target vessel failure was 17% (51 of 292) in the DES group versus 19% (58 of 305) in the BMS group (adjusted hazard ratio 0·92, 95% CI 0·63-1·34, p=0·70). Between-group differences in the components of the primary endpoint, serious adverse events, or stent thrombosis were not significant. Enrolment was stopped before the revised target sample size of 762 patients was reached. INTERPRETATION: In patients undergoing stenting of de-novo SVG lesions, no significant differences in outcomes between those receiving DES and BMS during 12 months of follow-up were found. The study results have important economic implications in countries with high DES prices such as the USA, because they suggest that the lower-cost BMS can be used in SVG lesions without compromising either safety or efficacy. FUNDING: US Department of Veterans Affairs Cooperative Studies Program.


Subject(s)
Graft Rejection/drug therapy , Percutaneous Coronary Intervention/instrumentation , Saphenous Vein/surgery , Thrombosis/epidemiology , Aged , Double-Blind Method , Drug-Eluting Stents , Female , Humans , Male , Middle Aged , Self Expandable Metallic Stents , Thrombosis/etiology , Treatment Outcome
3.
N Engl J Med ; 369(20): 1892-903, 2013 Nov 14.
Article in English | MEDLINE | ID: mdl-24206457

ABSTRACT

BACKGROUND: Combination therapy with angiotensin-converting-enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) decreases proteinuria; however, its safety and effect on the progression of kidney disease are uncertain. Methods We provided losartan (at a dose of 100 mg per day) to patients with type 2 diabetes, a urinary albumin-to-creatinine ratio (with albumin measured in milligrams and creatinine measured in grams) of at least 300, and an estimated glomerular filtration rate (GFR) of 30.0 to 89.9 ml per minute per 1.73 m(2) of body-surface area and then randomly assigned them to receive lisinopril (at a dose of 10 to 40 mg per day) or placebo. The primary end point was the first occurrence of a change in the estimated GFR (a decline of ≥ 30 ml per minute per 1.73 m(2) if the initial estimated GFR was ≥ 60 ml per minute per 1.73 m(2) or a decline of ≥ 50% if the initial estimated GFR was <60 ml per minute per 1.73 m(2)), end-stage renal disease (ESRD), or death. The secondary renal end point was the first occurrence of a decline in the estimated GFR or ESRD. Safety outcomes included mortality, hyperkalemia, and acute kidney injury. Results The study was stopped early owing to safety concerns. Among 1448 randomly assigned patients with a median follow-up of 2.2 years, there were 152 primary end-point events in the monotherapy group and 132 in the combination-therapy group (hazard ratio with combination therapy, 0.88; 95% confidence interval [CI], 0.70 to 1.12; P=0.30). A trend toward a benefit from combination therapy with respect to the secondary end point (hazard ratio, 0.78; 95% CI, 0.58 to 1.05; P=0.10) decreased with time (P=0.02 for nonproportionality). There was no benefit with respect to mortality (hazard ratio for death, 1.04; 95% CI, 0.73 to 1.49; P=0.75) or cardiovascular events. Combination therapy increased the risk of hyperkalemia (6.3 events per 100 person-years, vs. 2.6 events per 100 person-years with monotherapy; P<0.001) and acute kidney injury (12.2 vs. 6.7 events per 100 person-years, P<0.001). Conclusions Combination therapy with an ACE inhibitor and an ARB was associated with an increased risk of adverse events among patients with diabetic nephropathy. (Funded by the Cooperative Studies Program of the Department of Veterans Affairs Office of Research and Development; VA NEPHRON-D ClinicalTrials.gov number, NCT00555217.).


Subject(s)
Angiotensin II Type 1 Receptor Blockers/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Diabetic Nephropathies/drug therapy , Lisinopril/therapeutic use , Losartan/therapeutic use , Adult , Angiotensin II Type 1 Receptor Blockers/adverse effects , Angiotensin-Converting Enzyme Inhibitors/adverse effects , Diabetic Nephropathies/complications , Diabetic Nephropathies/mortality , Double-Blind Method , Drug Therapy, Combination , Female , Glomerular Filtration Rate , Humans , Kaplan-Meier Estimate , Kidney Failure, Chronic/etiology , Lisinopril/adverse effects , Losartan/adverse effects , Male , Middle Aged
4.
Clin Ther ; 46(1): 40-49, 2024 01.
Article in English | MEDLINE | ID: mdl-37953077

ABSTRACT

PURPOSE: It takes 17 years, on average, for trial results to be implemented into practice. Using data from the Department of Veterans Affairs (VA), this study assessed the potential impact on clinical practice of the dissemination of findings from a randomized, controlled trial reporting harm with the use of combination therapy. Communication between research and VA Pharmacy Benefits Management Services (PBM)  provided the impetus for communication from the PBM about the findings of the trial in accordance with policy. METHODS: In this de-implementation study, interrupted time series analysis was used for assessing prescribing patterns and adverse clinical events before and after the dissemination of the trial findings. The de-implementation strategy was multicomponent and multilevel. Strategies were aligned with categories outlined in the Expert Recommendations for Implementing Change: train and educate stakeholders, use evaluative and iterative strategies, develop stakeholder inter-relationships, change infrastructure, provide interactive assistance, and engage consumers. VA patients with type 2 diabetes mellitus, chronic kidney disease stages 1 to 3, and a moderate or severe albuminuria who received care between July 2008 and November 2017 were included. Patients were subgrouped according to treatment with an angiotensin-converting enzyme inhibitor + angiotensin receptor blocker. The primary end point was the prevalence of combination therapy use. Secondary end points were the incidences of acute kidney injury and hyperkalemia. FINDINGS: This study followed 712,245 patients, 9297 of whom used combination therapy. Data were available from 428,535 and 283,710 patients pre- and post-intervention, respectively; among these, 8324 and 973 patients used combination therapy, the median ages were 66 and 68 years, and 96.92% and 98.82% were men. One month following communication from the PBM, the reductions in combination therapy users, acute kidney injury events, and hyperkalemia were 331.94 (95% CI, 500.27-163.32), 36.58% (95% CI, 31.90%-41.95%), and 25.49% (95% CI, 14.17%-36.07%) per 100,000 patients per month, respectively (all, P < 0.001), whereas before the communication, these changes were +14.84 (95% CI, 10.27-19.42), -3.46% (95% CI, 3.18-3.74), and -3.27% (95% CI, 2.66%-3.87%) (all, P < 0.001). IMPLICATIONS: The apparent speed and impact of the implementation of changes resulting from the dissemination of trial findings into VA clinical practice are encouraging. The speed of implementation was much faster than average for health care providers in the United States. Established communications between research and clinical practice, as well as established policy and communications between PBM and clinical practice, may be a model for other health care organizations.


Subject(s)
Acute Kidney Injury , Diabetes Mellitus, Type 2 , Hyperkalemia , Male , Humans , United States , Aged , Female , Diabetes Mellitus, Type 2/drug therapy , Hyperkalemia/chemically induced , Hyperkalemia/complications , Hyperkalemia/epidemiology , Interrupted Time Series Analysis , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Acute Kidney Injury/chemically induced , Acute Kidney Injury/epidemiology
5.
Biometals ; 25(5): 961-9, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22706571

ABSTRACT

Reticuloendothelial blockade in hemodialysis patients prevents optimal intravenous (IV) iron utilization. Vitamin C has emerged as a potential therapy to improve anemia treatment by enhancing iron mobilization. However, Vitamin C can act as a pro-oxidant in the presence of iron. This was a prospective, open-label, crossover study. Thirteen patients with end-stage renal disease on hemodialysis and four healthy controls were assigned to receive 100 mg of IV iron sucrose (IS) or 100 mg of IV IS co-administered with 300 mg of IV Vitamin C (IS + C) in random sequence. Serum samples for IL-1, IL-6, TNF-α and IL-10 and non-transferrin bound iron were obtained at baseline, 45 min and 105 min post study medication administration. Peripheral blood mononuclear cells were isolated at the same time points and stained with fluorescent probes to identify intracellular reactive oxygen species and mitochondrial membrane potential (Δψm) by flow cytometry. Lipid peroxidation was assessed by plasma F2-isoprosatane concentration. Both IS and IS + C were associated with increased plasma F2-isoprostanes concentrations post-infusion. Maximal plasma F2-isoprostane concentrations after IS + C were significantly elevated from baseline (234 ± 0.04 vs. 0.198 ± 0.028 ng/mL, p = 0.02). After IS + C, IL-1, IL-6, IL-10, and TNF-alpha were significantly elevated compared to baseline. After IS alone only IL-6 was noted to be elevated. Intracellular production of H(2)O(2) and loss of mitochondrial membrane potential (Δψm) was observed after IS while IS + C was associated with increased O (2) (·-) production. Both IS and IS + C induced serum cytokine activation accompanied by lipid peroxidation, however, IS + C induced higher plasma concentrations of F2-isoprostanes, IL-1, IL-10, and TNF-α post-infusion. Long-term safety studies of IV iron co-administered with Vitamin C are warranted.


Subject(s)
Ascorbic Acid/administration & dosage , Ferric Compounds/administration & dosage , Glucaric Acid/administration & dosage , Kidney Failure, Chronic/drug therapy , Kidney Failure, Chronic/metabolism , Adult , Cross-Over Studies , Cytokines/blood , Epoetin Alfa , Erythropoietin/administration & dosage , F2-Isoprostanes/blood , Female , Ferric Oxide, Saccharated , Humans , Infusions, Intravenous , Kidney Failure, Chronic/immunology , Lipid Peroxidation/drug effects , Male , Membrane Potential, Mitochondrial/drug effects , Middle Aged , Oxidative Stress/drug effects , Prospective Studies , Reactive Oxygen Species/blood , Recombinant Proteins/administration & dosage , Systems Biology
6.
PLoS One ; 17(5): e0267462, 2022.
Article in English | MEDLINE | ID: mdl-35511939

ABSTRACT

Non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen are among the most-frequently used medications. Although these medications have different mechanisms of action, they have similar indications and treatment duration has been positively correlated with cardiovascular risk although the degree of risk varies by medication. Our objective was to study treatment effects of chronic use of individual NSAID medications and acetaminophen on all-cause mortality among patients who tested positive for COVID-19 while accounting for adherence. We used the VA national datasets in this retrospective cohort study to differentiate between sporadic and chronic medication use: sporadic users filled an NSAID within the last year, but not recently or regularly. Using established and possible risk factors for severe COVID-19, we used propensity scores analysis to adjust for differences in baseline characteristics between treatment groups. Then, we used multivariate logistic regression incorporating inverse propensity score weighting to assess mortality. The cohort consisted of 28,856 patients. Chronic use of aspirin, ibuprofen, naproxen, meloxicam, celecoxib, diclofenac or acetaminophen was not associated with significant differences in mortality at 30 days (OR = 0.98, 95% CI: 0.95-1.00; OR = 0.99, 95% CI: 0.98-1.00; OR = 1.00, 95% CI: 0.98-1.01; OR = 0.99, 95% CI: 0.98-1.00; OR = 1.00, 95% CI: 0.98-1.01; OR = 0.99, 95% CI: 0.97-1.01; and OR = 1.00, 95% CI: 0.99-1.02, respectively) nor at 60 days (OR = 0.97, 95% CI: 0.95-1.00; OR = 1.00, 95% CI: 0.99-1.01; OR = 0.99, 95% CI: 0.98-1.01; OR = 0.99, 95% CI: 0.97-1.00; OR = 0.99, 95% CI: 0.97-1.01; OR = 0.99, 95% CI: 0.97-1.01; and OR = 1.01, 95% CI: 0.99-1.02, respectively). Although the study design cannot determine causality, the study should assure patients as it finds no association between mortality and chronic use of these medications compared with sporadic NSAID use among those infected with COVID-19.


Subject(s)
COVID-19 Drug Treatment , Veterans , Acetaminophen/adverse effects , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Humans , Retrospective Studies , United States/epidemiology
7.
Am J Cardiol ; 162: 24-30, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34736721

ABSTRACT

Saphenous vein grafts (SVGs) have high rates of in-stent restenosis (ISR). We compared the baseline clinical and angiographic characteristics of patients and lesions that did develop ISR with those who did not develop ISR during a median follow-up of 2.7 years in the DIVA study (NCT01121224). We also examined the ISR types using the Mehran classification. ISR developed in 119 out of the 575 DIVA patients (21%), with similar incidence among patients with drug-eluting stents and bare-metal stents (BMS) (21% vs 21%, p = 0.957). Patients in the ISR group were younger (67 ± 7 vs 69 ± 8 years, p = 0.04) and less likely to have heart failure (27% vs 38%, p = 0.03) and SVG lesions with Thrombolysis In Myocardial Infarction 3 flow before the intervention (77% vs 83%, p <0.01), but had a higher number of target SVG lesions (1.33 ± 0.64 vs 1.16 ± 0.42, p <0.01), more stents implanted in the target SVG lesions (1.52 ± 0.80 vs 1.31 ± 0.66, p <0.01), and longer total stent length (31.37 ± 22.11 vs 25.64 ± 17.42 mm, p = 0.01). The incidence of diffuse ISR was similar in patients who received drug-eluting-stents and BMS (57% vs 54%, p = 0.94), but BMS patients were more likely to develop occlusive restenosis (17% vs 33%, p = 0.05).


Subject(s)
Coronary Artery Bypass/adverse effects , Coronary Artery Disease/surgery , Coronary Restenosis/epidemiology , Drug-Eluting Stents/adverse effects , Graft Occlusion, Vascular/epidemiology , Saphenous Vein/transplantation , Age Factors , Aged , Coronary Angiography , Coronary Artery Disease/complications , Coronary Artery Disease/mortality , Coronary Restenosis/diagnosis , Female , Graft Occlusion, Vascular/diagnosis , Humans , Male , Middle Aged , Prosthesis Design , Risk Factors
8.
Biometals ; 24(4): 603-13, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21229380

ABSTRACT

Intravenous (IV) iron supplementation is widely used to support erythropoeisis in hemodialysis patients. IV iron products are associated with oxidative stress that has been measured principally by circulating biomarkers such as products of lipid peroxidation. The pro-oxidant effects of IV iron are presumed to be due at least in part, by free or non-transferrin bound iron (NTBI). However, the effects of IV iron on intracellular redox status and downstream effectors is not known. This prospective, crossover study compared cytokine activation, reactive oxygen species generation and oxidative stress after single IV doses of iron sucrose and iron dextran. This was a prospective, open-label, crossover study. Ten patients with end-stage renal disease (ESRD) on hemodialysis and four age and sex-matched healthy were assigned to receive 100 mg of each IV iron product over 5 min in random sequence with a 2 week washout between products. Subjects were fasted and fed a low iron diet in the General Clinical Research Center at the University of New Mexico. Serum and plasma samples for IL-1, IL-6, TNF-α and IL-10 and NTBI were obtained at baseline, 60 and 240 min after iron infusion. Peripheral blood mononuclear cells (PBMC) were isolated at the same time points and stained with fluorescent probes to identify intracellular reactive oxygen species and mitochondrial membrane potential (Δψm) by flow cytometry. Lipid peroxidation was assessed by plasma F(2) isoprostane concentration. Mean ± SEM maximum serum NTBI values were significantly higher among patients receiving IS compared to ID (2.59 ± 0.31 and 1.0 ± 0.36 µM, respectively, P = 0.005 IS vs. ID) Mean ± SEM NTBI area under the serum concentration-time curve (AUC) was 3-fold higher after IS versus ID (202 ± 53 vs. 74 ± 23 µM*min/l, P = 0.04) in ESRD patients, indicating increased exposure to NTBI. IV iron administration was associated with increased pro-inflammatory cytokines. Serum IL-6 concentrations increased most profoundly, with a 2.6 and 2.1 fold increase from baseline in ESRD patients given IS and ID, respectively (P < 0.05 compared to baseline). In healthy controls, serum IL-6 was undetectable at baseline and after IV iron administration. Most ESRD patients had increased intracellular ROS generation, however, there was no difference between ID and IS. Only one healthy control had increased ROS generation post IV iron. All healthy controls experienced a loss of Δψm (100% with IS and 50% with ID). ESRD patients also had loss of Δψm with a nadir at 240 min. IS administration was associated with higher maximum serum NTBI concentrations compared to ID, however, the both compounds produced similar ROS generation and cytokine activation that was more pronounced among ESRD patients. The effect of IV iron-induced ROS production on pivotal signaling pathways needs to be explored.


Subject(s)
Cytokines/immunology , Ferric Compounds/administration & dosage , Iron-Dextran Complex/administration & dosage , Iron/metabolism , Reactive Oxygen Species/metabolism , Renal Dialysis , Adult , Cross-Over Studies , Cytokines/blood , F2-Isoprostanes/blood , Female , Ferric Oxide, Saccharated , Glucaric Acid , Humans , Injections, Intravenous , Lipid Peroxidation/immunology , Male , Membrane Potential, Mitochondrial , Middle Aged , Molecular Weight , Prospective Studies
9.
BMJ Open ; 11(8): e053019, 2021 08 16.
Article in English | MEDLINE | ID: mdl-34400461

ABSTRACT

INTRODUCTION: Diabetic kidney disease (DKD) is the most frequent cause of end-stage renal disease (ESRD) in the USA and worldwide. Recent experimental and clinical data suggest that the non-specific phosphodiesterase inhibitor pentoxifylline (PTX) may decrease progression of chronic kidney disease. However, a large-scale randomised clinical trial is needed to determine whether PTX can reduce ESRD and death in DKD. METHODS AND ANALYSIS: Veterans Affairs (VA) PTXRx is a pragmatic, randomised, placebo-controlled multicentre VA Cooperative Study to test the hypothesis that PTX, when added to usual care, leads to a reduction in the time to ESRD or death in patients with type 2 diabetes with DKD when compared with usual care plus placebo. The study aims to enrol 2510 patients over a 4-year period with an additional up to 5-year follow-up to generate a total of 646 primary events. The primary objective of this study is to compare the time until ESRD or death (all-cause mortality) between participants randomised to PTX or placebo. Secondary endpoints will be: (1) health-related quality of life, (2) time to doubling of serum creatinine, (3) incidence of hospitalisations for congestive heart failure, (4) incidence of a three-point major adverse cardiovascular events composite (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke), (5) incidence of peripheral vascular disease, (6) change in urinary albumin-to-creatinine ratio from baseline to 6 months and (7) rate of annual change in estimated glomerular filtration rate (eGFR) during the study period. ETHICS AND DISSEMINATION: This study was approved by the VA Central Institutional Review Board (cIRB/18-36) and will be conducted in compliance with the Declaration of Helsinki and the Guidelines for Good Clinical Practice. The Hines Cooperative Studies Programme will finalise the study results, which will be published in accordance with the Consolidated Standards of Reporting Trials statement in a peer-reviewed scientific journal. TRIAL REGISTRATION NUMBER: NCT03625648.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Nephropathies , Pentoxifylline , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Diabetic Nephropathies/drug therapy , Glomerular Filtration Rate , Humans , Multicenter Studies as Topic , Pentoxifylline/therapeutic use , Quality of Life , Randomized Controlled Trials as Topic
10.
Curr Pharmacol Rep ; 6(3): 71-84, 2020.
Article in English | MEDLINE | ID: mdl-32399388

ABSTRACT

The purpose of this review was to assess the advancement of applications for physiologically based pharmacokinetic (PBPK) modeling in various therapeutic areas. We conducted a PubMed search, and 166 articles published between 2012 and 2018 on FDA-approved drug products were selected for further review. Qualifying publications were summarized according to therapeutic area, medication(s) studied, pharmacokinetic model type utilized, simulator program used, and the applications of that modeling. The results showed a 13-fold increase in the number of papers published from 2012 to 2018, with the largest proportion of articles dedicated to the areas of infectious diseases, oncology, and neurology, and application extensions including prediction of drug-drug interactions due to metabolism and/or transporter-mediated effects and understanding drug kinetics in special populations. In addition, we profiled several high-impact studies whose results were used to guide package insert information and formulate dose recommendations. These results show that while utilization of PBPK modeling has drastically increased over the past several years, regulatory support, lack of easy-to-use systems for clinicians, and challenges with model validation remain major challenges for the widespread adoption of this practice in institutional and ambulatory settings. However, PBPK modeling will continue to be a useful tool in the future to assess therapeutic drug monitoring and the growing field of personalized medicine.

11.
Eur J Drug Metab Pharmacokinet ; 44(3): 389-408, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30460522

ABSTRACT

BACKGROUND AND OBJECTIVES: Lamotrigine (Lamictal®) is a broad-spectrum antiepileptic drug available in both immediate-(IR) and extended-release (XR) formulations. Here, we present a new physiologically based pharmacokinetic (PBPK) model for IR and XR formulations of lamotrigine to predict disposition in adults and children, plus drug-drug interactions (DDIs). METHODS: Models for lamotrigine IR and XR formulations were constructed using a Simcyp® Simulator. Concentration-time profiles were simulated for lamotrigine IR single (SD) and steady-state (SS) doses ranging from 25 to 200 mg in adults, as well as 2 mg/kg (SD), and 7.7-9.4 mg/kg (SS) in children aged between 4 and 17 years. Lamotrigine XR profiles were simulated for SD and SS doses ranging from 250 to 400 mg. DDI prediction with lamotrigine was simulated in adults with enzyme-inducing drugs, rifampin (rifampicin) and ritonavir, as well as the enzyme inhibitor, valproic acid. RESULTS: The lamotrigine model predicted adult area-under-the-curve (AUC) and peak plasma concentration (Cmax) results for IR SD within 35% of observed data; lamotrigine IR SS dosing was within 10% and 30% of observed data, respectively. Pediatric lamotrigine IR SD AUC and Cmax values were within 10% and 15% of observed data, respectively. AUC and Cmax values for lamotrigine XR SD simulated in adults were within 20% of observed data; similarly lamotrigine XR SS parameters were within 10%. Concerning DDI simulation in adults, predicted-to-observed lamotrigine AUC ratios [AUCDDI/AUCalone] were within 15% for ritonavir and rifampin, and 20% for valproic acid. CONCLUSIONS: Our developed PBPK lamotrigine profile accurately predicts DDIs and lamotrigine IR/XR formulation disposition in adults and children. This PBPK model will be helpful in designing future DDI studies for co-administration of lamotrigine with other drugs and in designing individualized patient dosing regimens.


Subject(s)
Anticonvulsants/pharmacokinetics , Computer Simulation , Lamotrigine/pharmacokinetics , Models, Biological , Adult , Anticonvulsants/administration & dosage , Anticonvulsants/blood , Area Under Curve , Biological Availability , Child , Delayed-Action Preparations , Dose-Response Relationship, Drug , Drug Administration Schedule , Drug Interactions , Humans , Lamotrigine/administration & dosage , Lamotrigine/blood , Predictive Value of Tests
13.
Eur J Pharm Sci ; 111: 465-481, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-29030176

ABSTRACT

Valproic acid (VPA) is an older first-line antiepileptic drug with a complex pharmacokinetic (PK) profile, currently under investigation for several novel neurologic and non-neurologic indications. Our study objective was to design and validate a mechanistic model of VPA disposition in adults and children; and evaluate its predictive performance of drug-drug interactions (DDIs). This study expands upon existing physiologically based pharmacokinetic (PBPK) models for VPA by incorporating UGT enzyme kinetics and an advanced dissolution, absorption, and metabolism (ADAM) model for extended-release (ER) formulation. PBPK models for VPA IR and ER formulations were constructed using Simcyp Simulator (Version 15). First-order absorption was used for the immediate-release (IR) formulation and the ADAM model, including a controlled-release profile, for ER. Data from twenty-one published clinical studies were used to assess model performance. The model accurately predicted the concentration-time profiles of IR formulation for single-dose and steady-state doses ranging from 200mg to 1000mg. Similarly profiles were also simulated for ER formulation after a single-dose and steady-state doses of 500mg and 1000mg, respectively. In addition, simulated PK profiles agreed well with the observed data from studies in which VPA ER formulation was given to pediatric patients and VPA IR formulation to adult patients with cirrhosis. The model was further validated with individual adult data from a Phase I clinical trial consisting of eight cohorts after IV infusion of VPA with doses ranging from 15 to 150mg/kg. Co-administrations of VPA as an enzyme-inhibitor with victim drug phenytoin or lorazepam, as well as a substrate with enzyme inducer carbamazepine or phenobarbital, were simulated with the model to evaluate drug-drug interaction. The simulated serum concentration-time profiles were within the 5th and 95th percentiles, and the majority of the predicted area-under-the-curve (AUC) and peak plasma concentration (Cmax) values were within 25% of the reported average values. The comprehensive VPA PBPK model defined by this study may be used to support dosage regimen optimization to improve the safety and efficacy profile of this agent under different scenarios.


Subject(s)
Anticonvulsants/pharmacokinetics , Valproic Acid/pharmacokinetics , Anticonvulsants/administration & dosage , Caco-2 Cells , Computer Simulation , Dose-Response Relationship, Drug , Drug Interactions , Humans , Models, Biological , Monte Carlo Method , Tissue Distribution , Valproic Acid/administration & dosage
14.
Clin Cardiol ; 40(11): 946-954, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28841230

ABSTRACT

VA Cooperative Studies Program #571 (DIVA) was designed to evaluate the efficacy of drug-eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure when compared with bare-metal stents (BMS) in participants undergoing stenting of de novo SVG lesions. Participants undergoing clinically indicated stenting of de novo SVG lesions were randomized in a 1:1 ratio to DES or BMS. Randomization was stratified by presence/absence of diabetes mellitus and the number of target SVG lesions (1 vs ≥2) within each participating site. At sites that did not routinely administer 12-months of dual antiplatelet therapy after SVG stenting participants without acute coronary syndromes received 1 month of open-label clopidogrel, followed by 11 months of clopidogrel for those assigned to DES and 11 months of placebo for those assigned to BMS. The primary endpoint was the 12-month incidence of target-vessel failure (defined as the composite of cardiac death, target-vessel myocardial infarction, or target-vessel revascularization). Secondary endpoints included the incidence of other clinical endpoints and the incremental cost-effectiveness of DES relative to BMS. Due to lower-than-anticipated target-vessel failure rates, target enrollment was increased from 519 to 762. The study had randomized 599 participants when recruitment ended in December 2015. The DIVA trial will provide clarity on the appropriate stent type for de novo SVG lesions.


Subject(s)
Coronary Artery Bypass/adverse effects , Coronary Artery Disease/surgery , Drug-Eluting Stents , Graft Occlusion, Vascular/therapy , Metals , Percutaneous Coronary Intervention/instrumentation , Saphenous Vein/transplantation , Stents , Aged , Clinical Protocols , Coronary Artery Bypass/mortality , Coronary Artery Disease/mortality , Female , Graft Occlusion, Vascular/diagnostic imaging , Graft Occlusion, Vascular/mortality , Graft Occlusion, Vascular/physiopathology , Humans , Male , Middle Aged , Percutaneous Coronary Intervention/adverse effects , Percutaneous Coronary Intervention/mortality , Platelet Aggregation Inhibitors/administration & dosage , Prospective Studies , Prosthesis Design , Research Design , Risk Factors , Saphenous Vein/diagnostic imaging , Saphenous Vein/physiopathology , Time Factors , Treatment Outcome , United States , United States Department of Veterans Affairs , Vascular Patency
16.
Clin J Am Soc Nephrol ; 8(9): 1618-31, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23660180

ABSTRACT

Contrast-induced AKI (CI-AKI) is a common condition associated with serious, adverse outcomes. CI-AKI may be preventable because its risk factors are well characterized and the timing of renal insult is commonly known in advance. Intravenous (IV) fluids and N-acetylcysteine (NAC) are two of the most widely studied preventive measures for CI-AKI. Despite a multitude of clinical trials and meta-analyses, the most effective type of IV fluid (sodium bicarbonate versus sodium chloride) and the benefit of NAC remain unclear. Careful review of published trials of these interventions reveals design limitations that contributed to their inconclusive findings. Such design limitations include the enrollment of small numbers of patients, increasing the risk for type I and type II statistical errors; the use of surrogate primary endpoints defined by small increments in serum creatinine, which are associated with, but not necessarily causally related to serious, adverse, patient-centered outcomes; and the inclusion of low-risk patients with intact baseline kidney function, yielding low event rates and reduced generalizability to a higher-risk population. The Prevention of Serious Adverse Events following Angiography (PRESERVE) trial is a randomized, double-blind, multicenter trial that will enroll 8680 high-risk patients undergoing coronary or noncoronary angiography to compare the effectiveness of IV isotonic sodium bicarbonate versus IV isotonic sodium chloride and oral NAC versus oral placebo for the prevention of serious, adverse outcomes associated with CI-AKI. This article discusses key methodological issues of past trials investigating IV fluids and NAC and how they informed the design of the PRESERVE trial.


Subject(s)
Acute Kidney Injury/chemically induced , Acute Kidney Injury/prevention & control , Contrast Media/adverse effects , Randomized Controlled Trials as Topic/standards , Research Design/standards , Acetylcysteine/therapeutic use , Administration, Intravenous , Angiography/adverse effects , Free Radical Scavengers/therapeutic use , Humans , Sodium Bicarbonate/therapeutic use
17.
Expert Opin Drug Metab Toxicol ; 5(1): 71-81, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19236230

ABSTRACT

Hyperphosphatemia is recognized as a principal mineral disorder in chronic kidney disease (CKD) that leads to the development of secondary hyperparathyroidism. Recent data indicate that hyperphosphatemia is associated with accelerated cardiac calcification and increased mortality in patients with CKD. Control of serum phosphorus is accomplished with phosphate binder therapies that include calcium and aluminum salts. Recently, calcium-based binders have undergone reevaluation because of their association with cardiac calcification. The non-calcium, non-aluminum binder sevelamer hydrochloride has been associated with slower progression of cardiac calcification in clinical trials. Lanthanum carbonate is a newer phosphate binder with phosphate binding activity similar to aluminum salts making this agent a compelling alternative; however, more data are needed to evaluate long-term safety and effects on cardiovascular end points.


Subject(s)
Hyperphosphatemia/drug therapy , Lanthanum/chemistry , Lanthanum/therapeutic use , Phosphates/chemistry , Phosphates/metabolism , Bone and Bones/metabolism , Clinical Trials as Topic , Cognition/drug effects , Humans , Hyperphosphatemia/metabolism , Lanthanum/adverse effects , Lanthanum/metabolism , Lanthanum/pharmacology , Liver/metabolism
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