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Objectives: To perform an overview of the overlap of systematic reviews (SRs) assessing direct oral anticoagulants and characterize these reviews in terms of bias and methodological quality (PROSPERO: CRD42022316273)., Study Design and Setting: A PubMed-indexed search was performed from inception to January 31, 2022 to identify SRs evaluating direct oral anticoagulants in patients treated for an acute venous thromboembolism. The risk of bias of these SRs was assessed according to the Risk Of Bias In Systematic reviews tool. Redundancy was defined as overlap in terms of the type of population considered, the interventions compared, and the studies included., Results: A total of 144 SRs were evaluated, of which 26 (18.1%) were classified as original, 87 (60.4%) as conceptual replications, and 31 (21.5%) as excessive replications. The risk of bias was high in 19 (73.1%) of the original SRs, 65 (74.7%) of the conceptual replications, and 21 (67.7%) of the excessive replications. Compared to the original SRs, the overall methodological quality was not improved in either conceptual or excessive replications., Conclusion: A large number of SRs was classified as replications; a fifth constituted excessive replications. The replications showed no improvement in overall methodological quality compared to the original SRs., Competing Interests: Declaration of competing interest Céline Chapelle, Edouard Ollier, Paul Bonjean, Clara Locher, and Paul Jacques Zufferey: none. Michel Cucherat has received personal fees from Bayer and BMS for consulting. Silvy Laporte has received personal fees from Bayer for consulting, personal fees continuing medical education lectures from Pfizer, and personal fees for continuing medical education lectures from Eli Lilly., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Unfractionated heparin (UFH) is a widely used anticoagulant that possess numerous properties including anti-inflammatory, anti-viral, anti-angiogenesis, and anti-metastatic effects. The effect of this drug was evaluated on the podocyte, an important actor of the glomerular filtration. Using a functional approach, we demonstrate that heparin treatment leads to a functional podocyte perturbation characterized by the increase of podocyte monolayer permeability. This effect is enhanced with time of exposure. Proteomic study reveals that heparin down regulate focal adhesion and cytoskeletal protein expressions as well as the synthesis of glomerular basement membrane components. This study clearly demonstrates that UFH may affect podocyte function by altering cytoskeleton organization, cell-cell contacts and cell attachment., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background and Objectives: Randomized controlled trials (RCTs) are criticized for including patients who are overselected. Health authorities consequently encourage "real-world" postmarketing cohort studies. Our objective was to determine the differences between RCTs and observational studies as regards their populations and efficacy/safety results., Methods: A systematic review was conducted to identify RCTs and observational studies including patients with venous thromboembolism receiving direct oral anticoagulants or conventional treatment. Ratios of hazard ratio (RHR) comparing epidemiological studies (prospective and retrospective cohort studies and studies using living databases) with RCTs were computed., Results: Six RCTs (27,121 patients) and twenty observational studies (248,971 patients) were identified and analyzed. Prospective cohort studies seemed to recruit patients who were no less selected than those of RCTs whereas other types of observational studies may reflect the population treated in real life. Among observational studies, prospective cohort studies yielded the most favorable estimates of treatment effect compared with RCTs. These studies were associated with a nonsignificant 33% increase in efficacy estimate (RHR 0.67, [95% CI, 0.39-1.18]) but no effect on safety estimate. Studies using living databases were associated with nonsignificant trends toward a greater effect on efficacy (RHR 0.82, [0.66-1.01]) and a smaller effect on safety (RHR 1.33, [0.96-1.84])., Discussion: Overall, in this clinical setting, an exaggeration of the treatment efficacy estimate was seen with observational studies compared with RCTs., Conclusions: As the presence of residual confounding cannot be excluded, these results should be interpreted cautiously., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: An unexpected promising effect of low molecular weight heparins (LMWHs) on survival in patients with cancer was observed in early trials in post hoc subgroup analyses but not found in more recent trials. To highlight a possible regression over time toward the lack of the antitumoral effect of LMWHs, we performed a cumulative meta-analysis of survival data from randomized controlled trials (RCTs)., Study Design and Setting: Medical databases were searched to identify RCTs comparing, in patients with cancer, LMWHs with placebo or no treatment in patients free of venous thromboembolism (VTE), or to vitamin K antagonists in patients who experienced an acute VTE in overall survival. The cumulative hazard ratio (HR) was estimated after each study inclusion in chronological order., Results: Twenty-three studies (12,970 patients) were included. The cumulative meta-analysis of the earlier trials showed a significant improvement in overall survival with LMWHs. This apparent benefit then gradually regressed over time toward an absence of the effect of LMWHs on survival (HR: 0.98 [95% confidence interval, 0.93; 1.03])., Conclusion: Despite supportive experimental data and early clinical findings, the promising antitumoral effect of LMWHs in patients with cancer gradually vanished over time toward a lack of impact on overall survival. This result suggests 'p-hacking' and selective reporting of the positive results from post hoc subgroup analyses in the early studies., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The treatment of acute venous thromboembolism (VTE) is being completely modified with the development of direct oral anticoagulants (DOACs). Rivaroxaban, apixaban and edoxaban directly inhibit factor Xa, whereas dabigatran inhibits factor IIa. All these drugs are proposed orally, and share pharmacological similarities: fixed doses without any therapeutic drug monitoring, key role of the transporter proteins P-glycoprotein for all of them and metabolism mediated by CYP3A4 for the anti-Xa, short half-life with variable rate of renal elimination. More than 25 000 patients with acute VTE were included in phase-III studies. Rivaroxaban and apixaban challenged all the conventional therapy (parenteral heparins followed by anti-vitamin K antagonists) whereas edoxaban and dabigatran challenged only anti-vitamin K antagonists. All the DOACs met the non-inferiority efficacy endpoint (recurrent VTE during treatment), whereas the large non-inferiority margin was debated for dabigatran. However, they were associated with better safety and a decreased risk of major bleeding. According to indirect comparisons, there were no statistically significant differences between DOACs in terms of efficacy but some differences are not excluded in term of safety. Although DOACs allow for simplification of treatment in the majority of patients with acute VTE, their risk/benefit ratio is questioned in elderly patients, patients with mild-to-severe renal impairment, and in some clinical subgroups such as cancer or chronic thromboembolic pulmonary hypertension. Validated reversal strategies (potentially based on laboratory monitoring) are expected for patients with major bleeding, overdose or with a need for surgery., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Direct oral anticoagulants offer an alternative to vitamin K antagonist drugs in the prevention and treatment of thromboembolic events. Unlike the latter, they inhibit directly and specifically coagulation factors (Xa, IIa). Their pharmacological properties allow a fixed dose administration and no biological monitoring for the majority of patients. However, their pharmacokinetics dependent of membrane transporters (P-gp) and cytochrome P450 (CYP3A4) expose them to significant drug-drug interactions. Dose adjustment may then become necessary as in some clinical situations, such as kidney and liver failure. However, some questions remain open, particularly on the optimal handling of these molecules in some population (elderly patients, renal and hepatic impairment or polymedicated)., (© 2014 Société Française de Pharmacologie et de Thérapeutique.)

Apixaban is a direct oral anticoagulant (DOAC). Many studies have shown that it shows high pharmacokinetic interindividual and intraindividual variability (IIV). The risk of hemorrhage is a major concern for patients treated with apixaban to undergo an operation or an invasive procedure. Due to this large pharmacokinetic variability, the current recommendations concerning the optimal duration of apixaban discontinuation before a high‐bleeding risk procedure concern the general population and not a specific patient. The aim of this study was (1) to investigate by simulation the distribution of decay time of apixaban concentration and (2) to develop and validate an easy‐to‐use web tool to estimate the individual decay time of apixaban in a "real‐life" situation. A systematic review of the literature was conducted to select the relevant pharmacokinetic models for the creation of the web tool. For each model, pharmacokinetic profiles were simulated and the time to reach concentrations below the threshold of 30 ng/ml (T30) was calculated. One of the selected models was chosen to perform a Bayesian estimation and predict the optimal duration of apixaban discontinuation before a high‐bleeding risk procedure. All these results were concatenated into the PrevBleed application developed with the R Shiny package. [ABSTRACT FROM AUTHOR]

Objective: To quantify the impact of activated charcoal (AC) on rivaroxaban exposure in healthy volunteers.Methods: This was an open-label study with an incomplete cross-over design of single-dose rivaroxaban (40 mg) administered alone or with AC in 12 healthy volunteers. The study comprised three treatment periods in randomised sequence, one with rivaroxaban administered alone and two with AC given at 2, 5 or 8 h post-dose. Rivaroxaban plasma concentration was measured in blood samples drawn at 16 time points. The pharmacokinetic model of rivaroxaban alone or with AC administration was built using a non-linear mixed-effect modelling approach.Results: The pharmacokinetic model was based on a one-compartment model with an absorption rate described by the sum of three inverse Gaussian densities to reproduce multiphasic and prolonged absorption. The inclusion in the model of each AC administration schedule significantly improved objective function value. AC reduced the area under the rivaroxaban concentration-time curve by 43% when administered 2 h post-dose, by 31% when administered 5 h post-dose and by 29% when administered 8 h post-dose. Based on the estimated pharmacokinetic model, simulations suggested that AC might have an impact even after 8 h post-dose.Conclusion: AC administration significantly reduces exposure to rivaroxaban even if AC is administered 8 h after rivaroxaban. These results suggest that AC could be used in rivaroxaban overdose and accidental ingestion to antagonise absorption. CLINICALTRIAL.Gov Registration No: NCT02657512. [ABSTRACT FROM AUTHOR]

To quantify the drug-drug interactions between dabigatran etexilate (DE) and proton pump inhibitors (PPI) and in particular the role of P-gp activity modulation. In the first part of the study, efflux ratios of DE were evaluated using the caco-2 cell line in the presence of pantoprazole, omeprazole, rabeprazole, lansoprazole and ciclosporin A (positive control). The two PPI that reduced the efflux ratio of dabigatran to the greatest and least extent, respectively, were used during the second part of the study, comprising a single-centre, randomised, open-label study with an incomplete Latin square design. Nine healthy volunteers received DE (150 mg) alone, DE (150 mg) with the first PPI and DE (150 mg) with the second PPI in randomised sequence. Dabigatran plasma concentration and thrombin time were measured in blood samples withdrawn at 11 time points after each treatment. Models were built using a nonlinear mixed-effect modelling approach. Omeprazole and rabeprazole were the two PPI that reduced the efflux ratio of DE least and most, respectively. The PK model was based on an inverse Gaussian absorption process with one compartment. The relationship between dabigatran concentration and thrombin time was considered linear. Some PK profiles had dramatically low concentration values due to poor absorption. These profiles were clustered using a between subject model mixture with interoccasion variability. The concomitant administration of PPI did not significantly change dabigatran pharmacokinetics. DE is subject to high absorption variability, precluding evaluation of the effect of PPI on its pharmacokinetics. [ABSTRACT FROM AUTHOR]

Aim The aim of this study was to develop a PK/ PD model to assess drug-drug interactions between dabigatran and P-gp modulators, using the example of clarithromycin, a strong inhibitor of P-gp. Methods Ten healthy male volunteers were randomized to receive in the first treatment period a single 300 mg dose of dabigatran etexilate (DE) and in the second treatment period 500 mg clarithromycin twice daily during 3 days and then 300 mg DE plus 500 mg clarithromycin on the fourth day, or the same treatments in the reverse sequence. Dabigatran plasma concentration and ecarin clotting time ( ECT) were measured on 11 blood samples. Models were built using a non-linear mixed effect modelling approach. Results The best PK model was based on an inverse Gaussian absorption process with two compartments. The relationship between dabigatran concentration and ECT was implemented as a linear function. No continuous covariate was associated with a significant decrease in the objective function. The concomitant administration of clarithromycin induced a significant change only in DE bioavailability, which increased from 6.5% to 10.1% in the presence of clarithromycin. Clarithromycin increased peak concentration and AUC by 60.2% and 49.1% respectively. Conclusion The model proposed effectively describes the complex PK of dabigatran and takes into account drug-drug interactions with P-gp activity modulators, such as clarithromycin. [ABSTRACT FROM AUTHOR]