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British Journal of Clinical Pharmacology Feb 2021To present an updated overview on the safety of concurrent use of food, herbal or dietary supplement and warfarin. (Review)
Review
AIMS
To present an updated overview on the safety of concurrent use of food, herbal or dietary supplement and warfarin.
METHODS
A systematic literature review was performed on 5 databases from inception up to 31 December 2019. These interactions were classified depending on the likelihood of interaction and supporting evidences.
RESULTS
A total of 149 articles describing 78 herbs, food or dietary supplements were reported to interact with warfarin. These reports described potentiation with 45 (57.7%) herbs, food or dietary supplements while 23 (29.5%) reported inhibition and 10 (12.8%) reported limited impact on warfarin pharmacokinetics and pharmacodynamics. Twenty unique herb and dietary supplements also reported to result in minor bleeding events, such as purpura and gum bleeding as well as major events such as intracranial bleeding that led to death.
CONCLUSION
While most food, herbs and supplements can be safely taken in moderation, healthcare professionals should be aware of the increased risk of bleeding when taking several food and herbs. These include Chinese wolfberry, chamomile tea, cannabis, cranberry, chitosan, green tea, Ginkgo biloba, ginger, spinach, St. John's Wort, sushi and smoking tobacco. Patients should be counselled to continue to seek advice from their healthcare professionals when starting any new herbs, food or supplement.
Topics: Dietary Supplements; Ginkgo biloba; Herb-Drug Interactions; Humans; Phytotherapy; Warfarin
PubMed: 32478963
DOI: 10.1111/bcp.14404 -
British Journal of Clinical Pharmacology Nov 2021The objective of this paper is to systematically review the literature on drug-drug interactions with warfarin, with a focus on patient-important clinical outcomes. (Meta-Analysis)
Meta-Analysis Review
AIMS
The objective of this paper is to systematically review the literature on drug-drug interactions with warfarin, with a focus on patient-important clinical outcomes.
METHODS
MEDLINE, EMBASE and the International Pharmaceutical Abstract (IPA) databases were searched from January 2004 to August 2019. We included studies describing drug-drug interactions between warfarin and other drugs. Screening and data extraction were conducted independently and in duplicate. We synthesized pooled odds ratios (OR) with 95% confidence intervals (CIs), comparing warfarin plus another medication to warfarin alone. We assessed the risk of bias at the study level and evaluated the overall certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.
RESULTS
Of 42 013 citations identified, a total of 72 studies reporting on 3 735 775 patients were considered eligible, including 11 randomized clinical trials and 61 observational studies. Increased risk of clinically relevant bleeding when added to warfarin therapy was observed for antiplatelet (AP) regimens (OR = 1.74; 95% CI 1.56-1.94), many antimicrobials (OR = 1.63; 95% CI 1.45-1.83), NSAIDs including COX-2 NSAIDs (OR = 1.83; 95% CI 1.29-2.59), SSRIs (OR = 1.62; 95% CI 1.42-1.85), mirtazapine (OR = 1.75; 95% CI 1.30-2.36), loop diuretics (OR = 1.92; 95% CI 1.29-2.86) among others. We found a protective effect of proton pump inhibitors (PPIs) against warfarin-related gastrointestinal (GI) bleeding (OR = 0.69; 95% CI 0.64-0.73). No significant effect on thromboembolic events or mortality of any drug group used with warfarin was found, including single or dual AP regimens.
CONCLUSIONS
This review found low to moderate certainty evidence supporting the interaction between warfarin and a small group of medications, which result in increased bleeding risk. PPIs are associated with reduced hospitalization for upper GI bleeding for patients taking warfarin. Further studies are required to better understand drug-drug interactions leading to thromboembolic outcomes or death.
Topics: Anticoagulants; Drug Interactions; Gastrointestinal Hemorrhage; Humans; Pharmaceutical Preparations; Randomized Controlled Trials as Topic; Warfarin
PubMed: 33769581
DOI: 10.1111/bcp.14833 -
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 -
Annual Review of Pharmacology and... Jan 2024Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists, mostly warfarin, for the main indications for oral anticoagulation, prevention and... (Review)
Review
Direct oral anticoagulants (DOACs) have largely replaced vitamin K antagonists, mostly warfarin, for the main indications for oral anticoagulation, prevention and treatment of venous thromboembolism, and prevention of embolic stroke in atrial fibrillation. While DOACs offer practical, fixed-dose anticoagulation in many patients, specific restrictions or contraindications may apply. DOACs are not sufficiently effective in high-thrombotic risk conditions such as antiphospholipid syndrome and mechanical heart valves. Patients with cancer-associated thrombosis may benefit from DOACs, but the bleeding risk, particularly in those with gastrointestinal or urogenital tumors, must be carefully weighed. In patients with frailty, excess body weight, and/or moderate-to-severe chronic kidney disease, DOACs must be cautiously administered and may require laboratory monitoring. Reversal agents have been developed and approved for life-threatening bleeding. In addition, the clinical testing of potentially safer anticoagulants such as factor XI(a) inhibitors is important to further optimize anticoagulant therapy in an increasingly elderly and frail population worldwide.
Topics: Humans; Aged; Warfarin; Anticoagulants; Hemorrhage; Atrial Fibrillation; Renal Insufficiency, Chronic; Administration, Oral
PubMed: 37758192
DOI: 10.1146/annurev-pharmtox-032823-122811 -
Indian Journal of Dermatology,... 2016Anticoagulants are the cornerstone of treatment of venous thromboembolism associated with various medical conditions and surgical procedures. They act on different steps... (Review)
Review
Anticoagulants are the cornerstone of treatment of venous thromboembolism associated with various medical conditions and surgical procedures. They act on different steps of the coagulation pathway and are broadly categorized into heparins, vitamin K antagonists, and inhibitors of thrombin and factor Xa. The classification is evolving as newer and better oral and parenteral anticoagulants are being added. Anticoagulants in dermatology are important not only for their therapeutic application in cutaneous thrombotic dermatoses such as livedoid vasculitis, purpura fulminans, superficial and deep venous thrombosis and others but also for their use in non-thrombotic dermatoses such as lichen planus, recurrent oral aphthosis, chronic urticaria and several others. Further, the use of anticoagulants for any indication is associated with various adverse effects with dermatologic manifestations including specific reactions such as warfarin-induced skin necrosis, heparin-induced thrombocytopenia and anticoagulant-associated cholesterol embolization syndrome.
Topics: Anticoagulants; Dermatology; Heparin; Humans; Skin Diseases; Thromboembolism; Venous Thrombosis; Warfarin
PubMed: 27320765
DOI: 10.4103/0378-6323.184199 -
Pharmacotherapy Sep 2017Genotype-guided warfarin dosing algorithms are a rational approach to optimize warfarin dosing and potentially reduce adverse drug events. Diverse populations, such as... (Review)
Review
Genotype-guided warfarin dosing algorithms are a rational approach to optimize warfarin dosing and potentially reduce adverse drug events. Diverse populations, such as African Americans and Latinos, have greater variability in warfarin dose requirements and are at greater risk for experiencing warfarin-related adverse events compared with individuals of European ancestry. Although these data suggest that patients of diverse populations may benefit from improved warfarin dose estimation, the vast majority of literature on genotype-guided warfarin dosing, including data from prospective randomized trials, is in populations of European ancestry. Despite differing frequencies of variants by race/ethnicity, most evidence in diverse populations evaluates variants that are most common in populations of European ancestry. Algorithms that do not include variants important across race/ethnic groups are unlikely to benefit diverse populations. In some race/ethnic groups, development of race-specific or admixture-based algorithms may facilitate improved genotype-guided warfarin dosing algorithms above and beyond that seen in individuals of European ancestry. These observations should be considered in the interpretation of literature evaluating the clinical utility of genotype-guided warfarin dosing. Careful consideration of race/ethnicity and additional evidence focused on improving warfarin dosing algorithms across race/ethnic groups will be necessary for successful clinical implementation of warfarin pharmacogenomics. The evidence for warfarin pharmacogenomics has a broad significance for pharmacogenomic testing, emphasizing the consideration of race/ethnicity in discovery of gene-drug pairs and development of clinical recommendations for pharmacogenetic testing.
Topics: Anticoagulants; Ethnicity; Humans; Pharmacogenetics; Pharmacogenomic Variants; Polymorphism, Single Nucleotide; Warfarin
PubMed: 28672100
DOI: 10.1002/phar.1982 -
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 -
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 -
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