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Circulation Jan 2022Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer... (Randomized Controlled Trial)
Randomized Controlled Trial
Direct Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: Patient-Level Network Meta-Analyses of Randomized Clinical Trials With Interaction Testing by Age and Sex.
BACKGROUND
Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer substantial advantages over study-level data.
METHODS
We used individual patient data from the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database, which includes all patients randomized in the 4 pivotal trials of DOACs versus warfarin in atrial fibrillation (RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], and ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48]), to perform network meta-analyses using a stratified Cox model with random effects comparing standard-dose DOAC, lower-dose DOAC, and warfarin. Hazard ratios (HRs [95% CIs]) were calculated for efficacy and safety outcomes. Covariate-by-treatment interaction was estimated for categorical covariates and for age as a continuous covariate, stratified by sex.
RESULTS
A total of 71 683 patients were included (29 362 on standard-dose DOAC, 13 049 on lower-dose DOAC, and 29 272 on warfarin). Compared with warfarin, standard-dose DOACs were associated with a significantly lower hazard of stroke or systemic embolism (883/29 312 [3.01%] versus 1080/29 229 [3.69%]; HR, 0.81 [95% CI, 0.74-0.89]), death (2276/29 312 [7.76%] versus 2460/29 229 [8.42%]; HR, 0.92 [95% CI, 0.87-0.97]), and intracranial bleeding (184/29 270 [0.63%] versus 409/29 187 [1.40%]; HR, 0.45 [95% CI, 0.37-0.56]), but no statistically different hazard of major bleeding (1479/29 270 [5.05%] versus 1733/29 187 [5.94%]; HR, 0.86 [95% CI, 0.74-1.01]), whereas lower-dose DOACs were associated with no statistically different hazard of stroke or systemic embolism (531/13 049 [3.96%] versus 1080/29 229 [3.69%]; HR, 1.06 [95% CI, 0.95-1.19]) but a lower hazard of intracranial bleeding (55/12 985 [0.42%] versus 409/29 187 [1.40%]; HR, 0.28 [95% CI, 0.21-0.37]), death (1082/13 049 [8.29%] versus 2460/29 229 [8.42%]; HR, 0.90 [95% CI, 0.83-0.97]), and major bleeding (564/12 985 [4.34%] versus 1733/29 187 [5.94%]; HR, 0.63 [95% CI, 0.45-0.88]). Treatment effects for standard- and lower-dose DOACs versus warfarin were consistent across age and sex for stroke or systemic embolism and death, whereas standard-dose DOACs were favored in patients with no history of vitamin K antagonist use (=0.01) and lower creatinine clearance (=0.09). For major bleeding, standard-dose DOACs were favored in patients with lower body weight (=0.02). In the continuous covariate analysis, younger patients derived greater benefits from standard-dose (interaction =0.02) and lower-dose DOACs (interaction =0.01) versus warfarin.
CONCLUSIONS
Compared with warfarin, DOACs have more favorable efficacy and safety profiles among patients with atrial fibrillation.
Topics: Administration, Oral; Age Factors; Aged; Anticoagulants; Female; Humans; Male; Network Meta-Analysis; Randomized Controlled Trials as Topic; Risk Factors; Sex Factors; Warfarin
PubMed: 34985309
DOI: 10.1161/CIRCULATIONAHA.121.056355 -
The American Journal of Medicine May 2017Bariatric surgery may alter the absorption, distribution, metabolism, or elimination (disposition) of orally administered drugs via changes to the gastrointestinal tract... (Review)
Review
Bariatric surgery may alter the absorption, distribution, metabolism, or elimination (disposition) of orally administered drugs via changes to the gastrointestinal tract anatomy, body weight, and adipose tissue composition. As some patients who have undergone bariatric surgery will need therapeutic anticoagulation for various indications, appropriate knowledge is needed regarding anticoagulant drug disposition and resulting efficacy and safety in this population. We review general considerations about oral drug disposition in patients after bariatric surgery, as well as existing literature on oral anticoagulation after bariatric surgery. Overall, available evidence on therapeutic anticoagulation is very limited, and individual drug studies are necessary to learn how to safely and effectively use the direct oral anticoagulants. Given the sparsity of currently available data, it appears most prudent to use warfarin with international normalized ratio monitoring, and not direct oral anticoagulants, when full-dose anticoagulation is needed after bariatric surgery.
Topics: Absorption, Physiological; Administration, Oral; Anticoagulants; Bariatric Surgery; Biological Availability; Drug Monitoring; Energy Intake; Humans; Vitamin K; Warfarin; Weight Loss
PubMed: 28159600
DOI: 10.1016/j.amjmed.2016.12.033 -
BMJ (Clinical Research Ed.) Apr 2014Atrial fibrillation increases the risk of stroke, which is a leading cause of death and disability worldwide. The use of oral anticoagulation in patients with atrial... (Review)
Review
Atrial fibrillation increases the risk of stroke, which is a leading cause of death and disability worldwide. The use of oral anticoagulation in patients with atrial fibrillation at moderate or high risk of stroke, estimated by established criteria, improves outcomes. However, to ensure that the benefits exceed the risks of bleeding, appropriate patient selection is essential. Vitamin K antagonism has been the mainstay of treatment; however, newer drugs with novel mechanisms are also available. These novel oral anticoagulants (direct thrombin inhibitors and factor Xa inhibitors) obviate many of warfarin's shortcomings, and they have demonstrated safety and efficacy in large randomized trials of patients with non-valvular atrial fibrillation. However, the management of patients taking warfarin or novel agents remains a clinical challenge. There are several important considerations when selecting anticoagulant therapy for patients with atrial fibrillation. This review will discuss the rationale for anticoagulation in patients with atrial fibrillation; risk stratification for treatment; available agents; the appropriate implementation of these agents; and additional, specific clinical considerations for treatment.
Topics: Anticoagulants; Atrial Fibrillation; Benzimidazoles; Dabigatran; Hemorrhage; Humans; Medication Adherence; Morpholines; Pyrazoles; Pyridones; Risk Assessment; Rivaroxaban; Stroke; Thiophenes; Warfarin; beta-Alanine
PubMed: 24733535
DOI: 10.1136/bmj.g2116 -
Molecules (Basel, Switzerland) Nov 2021Warfarin sodium is a low-dose pharmaceutical blood thinner that exists in two forms: the clathrate form and the amorphous form. In commercially available warfarin sodium...
Warfarin sodium is a low-dose pharmaceutical blood thinner that exists in two forms: the clathrate form and the amorphous form. In commercially available warfarin sodium oral suspension, the active pharmaceutical ingredient (API) is added in the amorphous state. This study investigates the apparent instability of the commercially available warfarin liquid oral formulation using Raman and IR spectroscopy, X-ray diffraction, differential scanning calorimetry, UV spectroscopy, and optical microscopy. Warfarin, not its sodium salt, was identified as the undissolved solid existing in the suspension. This was found to be due to the dissociation of sodium salt and the protonation of the warfarin ion in the liquid phase, which triggered the crystallization of the sparingly soluble unsalted form. The coexistence of protonated and unprotonated warfarin ions in the supernatant, as detected by Raman and UV spectroscopy, confirmed this assumption. Study of the dissolution of warfarin sodium amorphous salt and crystalline sodium clathrate in the placebo and pure water verified the results. The effect of pH and temperature on warfarin precipitation was also explored.
Topics: Administration, Oral; Drug Compounding; Drug Stability; Molecular Structure; Particle Size; Warfarin
PubMed: 34771040
DOI: 10.3390/molecules26216631 -
Journal of Thrombosis and Haemostasis :... Jun 2015The utility of using genetic information to guide warfarin dosing has remained unclear based on prior observational studies and small clinical trials. Two larger trials... (Review)
Review
The utility of using genetic information to guide warfarin dosing has remained unclear based on prior observational studies and small clinical trials. Two larger trials of warfarin and one of the acenocoumarol and phenprocoumon have recently been published. The COAG trial addressed the incremental benefit of adding genetic information to clinical information and demonstrated no benefit from the pharmacogenetic-based dosing strategy on the primary outcome. The EU-PACT UK trial compared an algorithm approach using genetic and clinical information to one that used a relatively fixed starting dose. The pharmacogenetic-based algorithms improved the primary outcome. The study of acenocoumarol and phenprocoumon compared a pharmacogenetic with a clinical algorithm and demonstrated no benefit on the primary outcome. The evidence to date does not support an incremental benefit of adding genetic information to clinical information on anticoagulation control. However, compared with fixed dosing, a pharmacogenetic algorithm can improve anticoagulation control.
Topics: Algorithms; Anticoagulants; Blood Coagulation; Blood Coagulation Tests; Drug Dosage Calculations; Drug Monitoring; Genotype; Humans; Pharmacogenetics; Phenotype; Precision Medicine; Predictive Value of Tests; Treatment Outcome; Warfarin
PubMed: 26149035
DOI: 10.1111/jth.12978 -
Clinical Pharmacology and Therapeutics Dec 2022The objective of this study was to evaluate the evidence on cost-effectiveness of pharmacogenetic (PGx)-guided treatment for drugs with Clinical Pharmacogenetics...
The objective of this study was to evaluate the evidence on cost-effectiveness of pharmacogenetic (PGx)-guided treatment for drugs with Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines. A systematic review was conducted using multiple biomedical literature databases from inception to June 2021. Full articles comparing PGx-guided with nonguided treatment were included for data extraction. Quality of Health Economic Studies (QHES) was used to assess robustness of each study (0-100). Data are reported using descriptive statistics. Of 108 studies evaluating 39 drugs, 77 (71%) showed PGx testing was cost-effective (CE) (N = 48) or cost-saving (CS) (N = 29); 21 (20%) were not CE; 10 (9%) were uncertain. Clopidogrel had the most articles (N = 23), of which 22 demonstrated CE or CS, followed by warfarin (N = 16), of which 7 demonstrated CE or CS. Of 26 studies evaluating human leukocyte antigen (HLA) testing for abacavir (N = 8), allopurinol (N = 10), or carbamazepine/phenytoin (N = 8), 15 demonstrated CE or CS. Nine of 11 antidepressant articles demonstrated CE or CS. The median QHES score reflected high-quality studies (91; range 48-100). Most studies evaluating cost-effectiveness favored PGx testing. Limited data exist on cost-effectiveness of preemptive and multigene testing across disease states.
Topics: Humans; Pharmacogenomic Testing; Pharmacogenetics; Cost-Benefit Analysis; Warfarin; Carbamazepine
PubMed: 36149409
DOI: 10.1002/cpt.2754 -
Clinical Cardiology Apr 1990Warfarin and other 4-hydroxycoumarins are effective antithrombotic agents. They affect four blood coagulation proteins that act sequentially to produce thrombin.... (Review)
Review
Warfarin and other 4-hydroxycoumarins are effective antithrombotic agents. They affect four blood coagulation proteins that act sequentially to produce thrombin. Coumarin therapy decreases the biological activity of these proteins, and therefore decreases the rate at which blood clots. As the mechanism by which these drugs act has become clear, it has also been found that vitamin K will overcome the effects of coumarin anticoagulation and can be used to control bleeding side effects of coumarin therapy. Vitamin K is necessary for activity of a liver enzyme, the vitamin K-dependent carboxylase. A second enzyme that recycles an inactive to an active form of the vitamin is inhibited by coumarins. The ability of other liver enzymes to bypass the coumarin-sensitive step greatly enhances the safety of 4-hydroxycoumarins.
Topics: Humans; Vitamin K; Warfarin
PubMed: 2191810
DOI: No ID Found -
Einstein (Sao Paulo, Brazil) 2012Oral anticoagulants are among the drugs with the greatest number of drug interactions. The concomitant use of several medications is a common practice in patients with... (Review)
Review
Oral anticoagulants are among the drugs with the greatest number of drug interactions. The concomitant use of several medications is a common practice in patients with cardiovascular problems, who often also present with depression; therefore, the probability of an interaction occurring between warfarin and the antidepressants is high, and may result in increased or decreased anticoagulant activity. Since the possible interactions between these two classes of drugs have been poorly explored in literature, with a risk to the patients who use them, we reviewed the pharmacology of warfarin and its possible interactions with antidepressants. Of the antidepressants analyzed, those that showed relevant effects on the interaction with warfarin were, in decreasing order: paroxetine, venlafaxine, fluoxetine, and duloxetine.
Topics: Administration, Oral; Anticoagulants; Antidepressive Agents; Biotransformation; Cyclohexanols; Cytochrome P-450 Enzyme System; Drug Interactions; Duloxetine Hydrochloride; Fluoxetine; Hemorrhage; Humans; Paroxetine; Thiophenes; Thrombophilia; Venlafaxine Hydrochloride; Vitamin K; Warfarin
PubMed: 23045839
DOI: 10.1590/s1679-45082012000100024 -
Acta Pharmaceutica (Zagreb, Croatia) Sep 2020In this study, high-performance liquid chromatography with fluorescence detection (HPLC-FLD) has been used for the first time, for direct determination of warfarin and...
In this study, high-performance liquid chromatography with fluorescence detection (HPLC-FLD) has been used for the first time, for direct determination of warfarin and its major metabolite, 7-hydroxywarfarin, in rat plasma. The simple and sensitive method was developed using Fortis® reversed-phase diphenyl column (150 × 4.6 mm, 3 μm) and a mobile phase composed of phosphate buffer (25 mmol L-1)/methanol/acetonitrile (70:20:10, V/V/V), adjusted to pH 7.4, at a flow rate of 0.8 mL min-1. The diphenyl chemistry of the stationary phase provided a unique selectivity for separating the structurally related aromatic analytes, warfarin and 7-hydroxywarfarin, allowing their successful quantification in the complex plasma matrix. The method was linear over the range 0.01-25 μg mL-1, for warfarin and 7-hydroxywarfarin, and was found to be accurate, precise and selective in accordance with US FDA guidance for bioanalytical method validation. The method was sensitive enough to quantify 0.01 μg mL-1 of warfarin and 7-hydroxywarfarin (LLOQ) using only 100 μL of plasma. The applicability of this method was demonstrated by analyzing samples obtained from rats after oral administration of a single warfarin dose, and studying warfarin and 7-hydroxywarfarin pharmacokinetics.
Topics: Administration, Oral; Animals; Anticoagulants; Chromatography, High Pressure Liquid; Male; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Warfarin
PubMed: 32074068
DOI: 10.2478/acph-2020-0025 -
PloS One 2017The aim of this study was to systematically review data regarding pharmacokinetic (PK)-pharmacodynamic (PD) parameters from randomized controlled trials relating to... (Review)
Review
OBJECTIVES
The aim of this study was to systematically review data regarding pharmacokinetic (PK)-pharmacodynamic (PD) parameters from randomized controlled trials relating to interactions between herbal medicines and warfarin.
METHODS
Three electronic databases were searched to identify relevant trials. Two reviewers independently performed the study selection and data extraction. The risk of bias and reporting quality were also assessed independently by two reviewers using the Cochrane risk of bias tool and the consolidated standards of reporting trials (CONSORT). Outcomes were measured for all reported PK-PD parameters and adverse events.
RESULTS
Nine randomized controlled trials met our inclusion criteria. Most of the included studies were unclear regarding the risk of bias and had a low quality of methodology. Using CONSORT, the reporting percentages for the articles ranged from 36.5% to 61.5% and the mean percentage for all articles was 45.6%. St John's wort and echinacea affected the PK parameters of warfarin. Ginseng, ginger, garlic, and cranberry had no significant effect on the PK parameters. American ginseng altered the PD parameters of warfarin. St John's wort, ginseng, Korea red ginseng, ginkgo, ginger, garlic, aged garlic, and echincea did not significantly alter the PD parameters. Studies of ginkgo and cranberry showed conflicting results on the PK parameters and PD parameters, respectively. The incidence of adverse events in all trials was low and no major adverse events were reported.
CONCLUSIONS
It was difficult to determine whether ten herbal medicines had significant effects on the PK-PD parameters of warfarin. Low quality of evidence, different compounds within and different compositions of the herbs, and methodological limitations of the crossover study, which is a clinical study in which subjects receive a sequence of different interventions, made it difficult to form conclusions. Additional studies that remedy these vulnerabilities are necessary to verify these results.
Topics: Anticoagulants; Herb-Drug Interactions; Humans; Plant Extracts; Randomized Controlled Trials as Topic; Thromboembolism; Treatment Outcome; Warfarin
PubMed: 28797065
DOI: 10.1371/journal.pone.0182794