DiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesDisciplines and OccupationsHealth Care
WarfarinAnticoagulantsVitamin K Epoxide ReductasesProthrombin TimeHemorrhageThromboembolismAtrial FibrillationMixed Function Oxygenasesbeta-AlanineVitamin KAryl Hydrocarbon HydroxylasesRodenticidesPharmacogeneticsStrokeVitamin K 1AspirinDrug MonitoringDrug InteractionsDrug Dosage Calculations4-HydroxycoumarinsIntracranial HemorrhagesBenzimidazolesBlood CoagulationEmbolismHerb-Drug InteractionsAdministration, OralVenous ThrombosisCarbon-Carbon LigasesRodent ControlAcenocoumarolPlatelet Aggregation InhibitorsThrombosisThrombophlebitisVitamin K DeficiencyDose-Response Relationship, DrugPhenylbutazoneTreatment OutcomePyridonesVenous ThromboembolismHeparin, Low-Molecular-Weight
Atrial fibrillationAnticoagulantsClinicalPrevent blood clotsVKORC1RodenticideTherapeuticAnticoagulant activityRodenticidesOutcomesInternational normaMyocardial infarctionActivity of warfarinInteract with warfarinTreatment with warfarinSensitivityDabigatran and warfarinAnticoagulation with warfarinAdverseClinicallyMedicationGeneticTaking WarfarinCoumadin and JantovenUnchanged warfarin doseVitaminCYP2C9EfficacyStrokeCommonlyMajor BleedsMechanismDoses of warfarinRare complicationResponse to warfarinTherapy with warfarinMetabolism of warfarinComplicationSodiumToxicityProthrombinThrombusTake warfarinBleeding RiskVersus warfarinPredictEmbolismAnaloguesPrevention
Atrial fibrillation22
Anticoagulants10
  • Eisenhower's treatment kickstarted a transformation in medicine whereby coronary artery disease, arterial plaques, and ischemic strokes were treated and protected against by using anticoagulants such as warfarin. (wikipedia.org)
  • The availability of oral, non-vitamin K based anticoagulants that provide similar protection against thrombosis but have fewer adverse side effects and do not require regular monitoring of INR has decreased the use of warfarin, particularly in the elderly who are most prone to bleeding complications. (nih.gov)
  • Additionally, although warfarin is no longer used primarily as a rodenticide, several long-acting coumarin derivatives (the so-called superwarfarin anticoagulants, such as brodifacoum, diphenadione, chlorophacinone, and bromadiolone) are used for this purpose and can produce profound and prolonged anticoagulation. (medscape.com)
  • Future studies are needed to understand the mechanism by which obesity increases bleeding risk for patients on warfarin and whether similar risks exist for the novel oral anticoagulants," Ogunsua and colleagues conclude. (medscape.com)
  • Warfarin has been the most commonly used oral anticoagulants ever since its approval in 1954 [ 1 ]. (hindawi.com)
  • Given these data, one would expect that SSRIs could increase the bleeding risk in patients receiving warfarin or other anticoagulants, and there is new evidence that adds to our understanding of this interaction. (pharmacytimes.com)
  • Their study, published online today in the Journal of the American College of Cardiology, is the most recent in a series of studies seeking to determine the safety and efficacy of non-vitamin K antagonist oral anticoagulants versus the long-standard warfarin. (medindia.net)
  • However, our findings indicate that the non-vitamin K antagonist oral anticoagulants as a group are associated with less injury to kidneys than warfarin. (medindia.net)
  • However, the researchers took it a step further and separated out the patients taking non-vitamin K antagonist oral anticoagulants from those taking warfarin. (medindia.net)
  • Since non-vitamin K antagonist oral anticoagulants have a different drug mechanism than warfarin, researchers have hypothesized that non-vitamin K antagonist oral anticoagulants may be related to better renal outcomes. (medindia.net)
Clinical21
  • From results of clinical studies, genetic variation in the CYP2C9 and/or VKORC1 genes can, in concert with clinical factors, predict how each individual responds to warfarin. (cms.gov)
  • This paper presents an update overview of clinical findings regarding herb-warfarin interaction, highlighting clinical outcomes, severity of documented interactions, and quality of clinical evidence. (hindawi.com)
  • In summary, herb-warfarin interaction, especially the clinical effects of herbs on warfarin therapy should be further investigated through multicenter studies with larger sample sizes. (hindawi.com)
  • The potency shown in clinical use boosts the studies on the mechanisms of warfarin anticoagulation. (hindawi.com)
  • Use of warfarin is still limited despite the strong evidence for its clinical value. (hindawi.com)
  • A literature survey over the herb-drug interactions in clinical cases showed that warfarin accounted for 34 of the total 133 cases of interactions, making itself the most frequently involved drug in herb-drug interactions [ 6 ]. (hindawi.com)
  • The incidence of interaction between herbs and warfarin is not yet fully known, and there is no body of reliable information currently available to draw upon when assessing the scale of any possible problem or predicting clinical outcomes. (hindawi.com)
  • Herb-warfarin interaction has considerable clinical significance, so it is especially necessary to identify the herbs that interact with warfarin. (hindawi.com)
  • Small studies and case reports indicate that heart failure, cancer and febrile illness may alter warfarin metabolism, with potentially important clinical results. (aafp.org)
  • In 297 patients starting warfarin therapy, we assessed CYP2C9 genotypes (CYP2C9 *1, *2, and *3), VKORC1 haplotypes (designated A and non-A), clinical characteristics, response to therapy (as determined by the international normalized ratio [INR]), and bleeding events. (nih.gov)
  • Conclusions: Unfavorable interaction between warfarin and PPI was negligible in clinical use. (scirp.org)
  • Nonetheless, for now we should assume that SSRIs do increase the risk of bleeding in individuals taking warfarin, and make clinical decisions accordingly. (pharmacytimes.com)
  • Combining genetic data with clinical information to determine the initial dosage of the blood thinner warfarin, used to prevent blood clots in the circulatory system, was no more effective in achieving stable anticoagulation than using only clinical information, according to a National Institutes of Health-funded clinical trial. (nih.gov)
  • This is especially true for complex drugs like warfarin whose action in our bodies is influenced by a variety of genetic, clinical and environmental factors. (nih.gov)
  • Based on these studies, dosing formulas have been developed that incorporate a person's genetic profile along with the patient's clinical characteristics to try and better predict the proper dose of warfarin - an approach known as pharmacogenetics. (nih.gov)
  • Given the lack of definitive information on whether or not pharmacogenetics can improve the care of patients and the need to study a broad range of patients being treated with warfarin, we needed a large clinical trial like COAG to help resolve this important question," said Stephen Kimmel, M.D., of the Perelman School of Medicine at the University of Pennsylvania and principal investigator of the COAG trial. (nih.gov)
  • In response, several controlled, clinical pharmacokinetic, and pharmacodynamic studies have been published in scientific literature and did not show a clinically relevant interaction between cranberry juice and either warfarin metabolism or INR in subjects on warfarin. (cranberryinstitute.org)
  • Aetna currently does not cover diagnostic genetic tests for warfarin because the clinical value of this type of genetic testing has not been established," an Aetna spokesperson said. (genomeweb.com)
  • In response to CMS' NCA, around 75 percent of respondents said CMS should cover such tests because there is sufficient clinical evidence showing that PGx-based warfarin dosing would reduce adverse events and save healthcare dollars in the long run. (genomeweb.com)
  • Principal investigator Professor George Dangas of the Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, US said: "Overall, this trial showed the noninferiority of edoxaban compared to warfarin (or similar analogues) with respect to the composite efficacy endpoint of adverse clinical events. (escardio.org)
  • CADTH has undertaken an optimal use project to assess the clinical and economic impact of point-of-care (POC) testing of the international normalized ratio (INR) for patients taking warfarin or other vitamin K antagonists. (cadth.ca)
Prevent blood clots3
  • Doctors prescribe warfarin to treat and prevent blood clots. (medicalnewstoday.com)
  • Warfarin is an anti-coagulant that is commonly used to prevent blood clots and embolism. (news-medical.net)
  • cholestatic hepatitis has been found to occur in patients taking both warfarin and ticlopidine (a drug that also helps to prevent blood clots), at the same time. (drugwatch.com)
VKORC116
  • Because the mechanism involves enzymes such as VKORC1, patients on warfarin with polymorphisms of the enzymes may require adjustments in therapy if the genetic variant that they have is more readily inhibited by warfarin, thus requiring lower doses. (wikipedia.org)
  • Certain common changes (polymorphisms) in the CYP2C9 and VKORC1 genes account for most of the variation in warfarin metabolism due to genetic factors. (medlineplus.gov)
  • Warfarin prevents (inhibits) the action of the VKORC1 enzyme and slows the activation of clotting proteins and clot formation. (medlineplus.gov)
  • Individuals develop warfarin sensitivity because a lower warfarin dose is needed to inhibit the VKORC1 enzyme, as there is less functional enzyme that needs to be suppressed. (medlineplus.gov)
  • While changes in specific genes, particularly CYP2C9 and VKORC1 , affect how the body reacts to warfarin, many other factors, including sex, age, weight, diet, and other medications, also play a role in the body's interaction with this drug. (medlineplus.gov)
  • Warfarin affects the vitamin K-dependent clotting factors II, VII, IX, and X. Warfarin is thought to interfere with clotting factor synthesis by inhibition of the C1 subunit of the vitamin K epoxide reductase (VKORC1) enzyme complex, thereby reducing the regeneration of vitamin K1 epoxide. (cms.gov)
  • Pharmacogenomic testing of CYP2C9 or VKORC1 alleles to predict a patient's response to warfarin occurs ideally prior to initiation of the drug. (cms.gov)
  • Prospectively, in Medicare-aged subjects whose warfarin therapy management includes pharmacogenomic testing of CYP2C9 or VKORC1 alleles to predict warfarin response, what is the frequency and severity of the following outcomes, compared to subjects whose warfarin therapy management does not include pharmacogenomic testing? (cms.gov)
  • Genetic variants of the enzyme that metabolizes warfarin, cytochrome P-450 2C9 (CYP2C9), and of a key pharmacologic target of warfarin, vitamin K epoxide reductase (VKORC1), contribute to differences in patients' responses to various warfarin doses, but the role of these variants during initial anticoagulation is not clear. (nih.gov)
  • Both the CYP2C9 genotype and VKORC1 haplotype had a significant influence on the required warfarin dose after the first 2 weeks of therapy. (nih.gov)
  • Initial variability in the INR response to warfarin was more strongly associated with genetic variability in the pharmacologic target of warfarin, VKORC1, than with CYP2C9. (nih.gov)
  • Recent research has suggested that variants of two genes, CYP2C9 and VKORC1, may be important in selecting the dose of warfarin needed for individual patients. (nih.gov)
  • The Carlsbad, Calif.-based firm's Infiniti Warfarin XP dose-response assay for identifying patients with CYP450 2C9 and VKORC1 genetic variants received 510(k) clearance from the FDA last January [see PGx Reporter 01-30-2008 ]. (genomeweb.com)
  • As an example, warfarin is the most cited therapeutic in relation to the genes CYP2C9 and VKORC1 . (cdc.gov)
  • The CYP2C9 and VKORC1 genes play a key role in the metabolism of warfarin. (cdc.gov)
  • Many studies have found evidence that variants in CYP2C9 and VKORC1 can impact the efficacy of warfarin in individual patients. (cdc.gov)
Rodenticide2
  • Title : Idea exchange: Present status of warfarin as a rodenticide Personal Author(s) : Hayes, Wayland J., 1917-1993. (cdc.gov)
  • In exposure-response models with up to five exposure categories, we saw evidence of an exposure-response relationship for several pesticides including the commonly used herbicides 2,4-D and glyphosate, the insecticides permethrin and carbaryl and the rodenticide warfarin. (cdc.gov)
Therapeutic6
  • intervals between tests can be lengthened if the patient manages stable therapeutic INR levels on an unchanged warfarin dose. (wikipedia.org)
  • However, the optimal dosing for obese patients is unknown, although it takes longer to obtain a therapeutic INR when warfarin is started, and obese patients require a higher maintenance dose. (medscape.com)
  • Concomitant use of warfarin, a highly efficacious oral anticoagulant, and herbs causes major safety concerns due to the narrow therapeutic window of warfarin. (hindawi.com)
  • The study outcomes were the time to the first INR within the therapeutic range, the time to the first INR of more than 4, the time above the therapeutic INR range, the INR response over time, and the warfarin dose requirement. (nih.gov)
  • To assess the relative effectiveness and safety of rivaroxaban versus warfarin in a large health system and to evaluate this association by time in therapeutic range (TTR). (bvsalud.org)
  • Under real-world conditions, warfarin and rivaroxaban were associated with similar safety and effectiveness , even among those with suboptimal therapeutic control. (bvsalud.org)
Anticoagulant activity2
  • CYP2C9 is the principal cytochrome P450 enzyme that modulates the anticoagulant activity of warfarin. (cms.gov)
  • Zhou, Q. and Chan, E. (2003) Effect of Omeprazole on the Anticoagulant Activity and the Pharmacokinetics of Warfarin Enantiomers in Rats. (scirp.org)
Rodenticides2
Outcomes4
  • Finding insufficient evidence demonstrating that pharmacogenomics-guided warfarin dosing improves health outcomes for Medicare beneficiaries, the Centers for Medicare & Medicaid Services this week determined that pharmacogenomic testing to predict warfarin responsiveness is "not reasonable and necessary. (genomeweb.com)
  • Instead, CMS proposed a more "appropriate" alternative, employing a "coverage with evidence development" strategy, in which it would pay for PGx-based warfarin dosing only for Medicare beneficiaries who are part of a prospectively designed, randomized-controlled trial showing pharmacogenomics-guided dosing strategies improve health outcomes over standard dosing methods. (genomeweb.com)
  • A CED decision from CMS on genetic testing for warfarin could signal private payors to hold off on covering genetic testing in this area until large, randomized, prospective studies are completed, yielding more convincing outcomes data. (genomeweb.com)
  • Two prior randomized controlled trials compared outcomes in patients treated with LAAC with outcomes with warfarin. (the-hospitalist.org)
International norma2
  • Note that antidepressants are not likely to affect the international normalized ratio in patients on warfarin. (pharmacytimes.com)
  • To quantify the risk for bleeding complications after thrombolysis for ischemic stroke in patients on warfarin (international normalized ratio [INR] ≤1.7) and to put these data into perspective with previous studies. (neurology.org)
Myocardial infarction1
  • Warfarin is highly effective in preventing and treating deep venous thrombosis and can meliorate symptoms in patients suffering from arterial fibrillation, prosthetic heart valves, indwelling central venous catheters, and myocardial infarction [ 2 ]. (hindawi.com)
Activity of warfarin1
  • However, different polymorphisms affect the activity of warfarin to varying degrees. (medlineplus.gov)
Interact with warfarin3
  • Many other medications and dietary factors can interact with warfarin, either increasing or decreasing its effectiveness. (wikipedia.org)
  • The high degree of protein binding is one of several mechanisms whereby other drugs interact with warfarin. (medscape.com)
  • Four herbs were considered as highly probable to interact with warfarin (level I), three were estimated as probable (level II), and ten and twenty-one were possible (level III) and doubtful (level IV), respectively. (hindawi.com)
Treatment with warfarin5
  • The degree of effect on the vitamin K ̶ dependent proteins depends on the dose and duration of treatment with warfarin. (medscape.com)
  • Because warfarin also reduces the activity of anticoagulant proteins C and S, a transient hypercoagulable state may occur shortly after treatment with warfarin is started. (medscape.com)
  • For patients with a DVT or PE secondary to a transient (reversible) risk factor, treatment with warfarin for 3 months is recommended. (druglib.com)
  • For patients with an unprovoked DVT or PE, treatment with warfarin is recommended for at least 3 months. (druglib.com)
  • For patients with two episodes of unprovoked DVT or PE, long-term treatment with warfarin is recommended. (druglib.com)
Sensitivity13
  • Warfarin sensitivity is a condition in which individuals have a low tolerance for the drug warfarin. (medlineplus.gov)
  • Many people with warfarin sensitivity take longer than normal to break down (metabolize) warfarin. (medlineplus.gov)
  • Other people with warfarin sensitivity do not need as much drug to prevent clots because their clot-forming process is naturally slower than average and can be stopped by low warfarin doses. (medlineplus.gov)
  • If people with warfarin sensitivity take the average dose (or more) of warfarin, they are at risk of an overdose, which can cause abnormal bleeding in the brain, gastrointestinal tract, or other tissues, and may lead to serious health problems or death. (medlineplus.gov)
  • Warfarin sensitivity does not appear to cause any health problems other than those associated with warfarin drug treatment. (medlineplus.gov)
  • The prevalence of warfarin sensitivity is unknown. (medlineplus.gov)
  • While it is unclear how many of these events are due to warfarin sensitivity, the most common sign is excessive internal bleeding, which often occurs when individuals with warfarin sensitivity are given too much of the medication. (medlineplus.gov)
  • The polymorphisms associated with warfarin sensitivity often differ by population and ethnic background. (medlineplus.gov)
  • As a result, the drug remains active in the body for a longer period of time, leading to warfarin sensitivity. (medlineplus.gov)
  • which means one copy of the altered gene in each cell is sufficient to result in warfarin sensitivity. (medlineplus.gov)
  • Additionally, people who have more than one polymorphism in a gene or polymorphisms in multiple genes associated with warfarin sensitivity have a lower tolerance for the drug's effect or take even longer to clear the drug from their body. (medlineplus.gov)
  • Certain genetic variations, SNPs, also affect warfarin sensitivity and metabolism. (news-medical.net)
  • puzzling as these studies are generally covered by grants," said Ramanath Vairavan, senior VP of sales and marketing for AutoGenomics, one of several companies marketing a genetic test for warfarin sensitivity. (genomeweb.com)
Dabigatran and warfarin1
  • We look at the data, and then discuss what we as individuals would do when making a decision between dabigatran and warfarin. (therapeuticseducation.org)
Anticoagulation with warfarin5
  • The authors urge physicians to consider the effect of concomitant disease as well as food or drug interactions when monitoring anticoagulation with warfarin. (aafp.org)
  • In patients with non-valvular AF that is persistent or paroxysmal and at high risk of stroke (i.e., having any of the following features: prior ischemic stroke, transient ischemic attack, or systemic embolism, or 2 of the following risk factors: age greater than 75 years, moderately or severely impaired left ventricular systolic function and/or heart failure, history of hypertension, or diabetes mellitus), long-term anticoagulation with warfarin is recommended. (druglib.com)
  • In patients with non-valvular AF that is persistent or paroxysmal and at an intermediate risk of ischemic stroke (i.e., having 1 of the following risk factors: age greater than 75 years, moderately or severely impaired left ventricular systolic function and/or heart failure, history of hypertension, or diabetes mellitus), long-term anticoagulation with warfarin is recommended. (druglib.com)
  • For patients with AF and mitral stenosis, long-term anticoagulation with warfarin is recommended. (druglib.com)
  • Lingual hematoma threatening airway obstruction in a patient on oral anticoagulation with warfarin. (pneumotox.com)
Adverse3
  • Of the approximately 2 million people in the U.S. who are prescribed warfarin annually, 35,000 to 45,000 individuals go to hospital emergency rooms with warfarin-related adverse drug events. (medlineplus.gov)
  • Herbal medicines and food interaction are now cited as the main cause of adverse events with warfarin. (hindawi.com)
  • The CED proposal follows a national coverage assessment notice that CMS issued last August, asking the public to weigh in on whether the government agency should pay for tests that determine which patients are genetically predisposed to experience an adverse reaction to warfarin [see PGx Reporter 10-29-2008 ]. (genomeweb.com)
Clinically7
  • Warfarin therapy is associated with rare instances of idiosyncratic, clinically apparent liver injury that are usually mild and rapidly reversible on stopping. (nih.gov)
  • Liver injury due to warfarin therapy is rare, but clinically apparent acute liver injury attributable to it has been reported. (nih.gov)
  • Clinically, warfarin is administered as a racemic mixture of the S - and R -enantiomers. (hindawi.com)
  • One study revealed that the mean half-life of warfarin is significantly reduced in patients with renal dysfunction, but the few studies of the effects of renal disease show no clinically relevant change in the response to warfarin. (aafp.org)
  • Warfarin is detected in breast milk in null or clinically insignificant amounts. (e-lactancia.org)
  • The vast majority of warnings about warfarin (a commonly prescribed anticoagulant) generated by a bar-code medication administration system were clinically insignificant. (ahrq.gov)
  • Our data suggest a statistically significant and clinically meaningful increase in the risk for symptomatic intracranial and major systemic bleedings among patients with stroke thrombolysis receiving warfarin up to the day of or day before stroke. (neurology.org)
Medication8
  • Warfarin is an anticoagulant used as a medication under several brand names including Coumadin. (wikipedia.org)
  • Warfarin is available as a generic medication and under many trade names. (wikipedia.org)
  • Warfarin is an anticoagulant medication that doctors prescribe to reduce the risk of blood clots, which may cause vein blockages, heart attack, and stroke. (medicalnewstoday.com)
  • Warfarin is a blood thinning medication that is sometimes used to help prevent a recurrent heart attack in people who cannot take aspirin or clopidogrel, or who have had a heart attack while taking those medications. (answers.com)
  • Warfarin is a very individualized medication without a "standard" dose. (ucsd.edu)
  • In October 2011, Bristol-Meyers Squibb submitted an updated Medication Guide to the FDA for approval with the omission of the warning to avoid cranberries and cranberry products based on the evidence that consumption of these foods with warfarin is safe. (cranberryinstitute.org)
  • Medication-error alerts for warfarin orders detected by a bar-code-assisted medication administration system. (ahrq.gov)
  • Although some research has suggested that warfarin increases the likelihood of heart attack, stroke and death for CKD patients, a new study found that the medication did not heighten these risks nor the risk of bleeding among those with impaired kidney function. (rxwiki.com)
Genetic2
  • Most major insurers do not yet cover genetic testing to gauge warfarin responsiveness for their beneficiaries. (genomeweb.com)
  • Meanwhile, at least one diagnostic firm with its hat in the warfarin genetic testing space expressed disappointment over CMS' proposal. (genomeweb.com)
Taking Warfarin14
  • It is essential to follow the instructions precisely and continue taking warfarin, even if the person feels well. (medicalnewstoday.com)
  • If hives, swelling, and difficulty breathing occur after taking warfarin, a person should seek emergency medical help. (medicalnewstoday.com)
  • Can you suffer a stroke if taking warfarin? (answers.com)
  • Yes, you can absolutely have a heart attack while taking warfarin. (answers.com)
  • There is also an increased risk of bleeding if taking warfarin along with aspirin or plavix. (answers.com)
  • Among them, 108 patients were taking warfarin for more than 6 weeks before and after PPI. (scirp.org)
  • 4-6 Now 2 recent reports agree with the positive studies, suggesting that SSRIs, and perhaps some other antidepressants, do in fact increase the incidence of serious bleeding in patients taking warfarin. (pharmacytimes.com)
  • Taken together, the bulk of the current evidence suggests that SSRIs are associated with an increased risk of bleeding in patients taking warfarin. (pharmacytimes.com)
  • The antidepressant mirtazapine is not considered an inhibitor of serotonin uptake (although it may cause release of serotonin), but in 1 study mirtazapine was associated with an increased risk of bleeding in patients taking warfarin. (pharmacytimes.com)
  • It does not appear necessary to avoid using SSRIs or other antidepressants in people taking warfarin, but the possibility of increased bleeding risk should be considered when selecting treatment for depression. (pharmacytimes.com)
  • Patients taking warfarin are required to undergo regular blood tests to monitor the drug's effectiveness. (drugwatch.com)
  • Dr. Carrero and team discovered that patients taking warfarin had a lower one-year composite risk of death, heart attack and stroke without a higher risk of bleeding compared to those who did not take warfarin. (rxwiki.com)
  • For those with severe CKD (measured as an eFGR of 15 to 30), 53.2 percent of the patients taking warfarin experienced death, heart attack, or stroke versus 61 percent of those who did not take warfarin. (rxwiki.com)
  • Point-of-Care INR Testing ― a newsletter article summarizing CADTH's work on POC INR testing for patients taking warfarin or other vitamin K antagonists. (cadth.ca)
Coumadin and Jantoven2
  • Brand names for warfarin are Coumadin and Jantoven. (medicalnewstoday.com)
  • Millions of Americans take the blood thinner warfarin (also known by the brand names Coumadin and Jantoven) to prevent and treat blood clots. (nyrealestatelawblog.com)
Unchanged warfarin dose1
  • The intervals between tests can be lengthened if the patient maintains stable target-range INR levels on an unchanged warfarin dose. (ucsd.edu)
Vitamin12
  • The effects of warfarin may be reversed with phytomenadione (vitamin K1), fresh frozen plasma, or prothrombin complex concentrate. (wikipedia.org)
  • Warfarin decreases blood clotting by blocking vitamin K epoxide reductase, an enzyme that reactivates vitamin K1. (wikipedia.org)
  • Warfarin is a commonly used oral anticoagulant with anti-vitamin K activity. (nih.gov)
  • The anticoagulation effects are currently believed to be due to warfarin interrupting the vitamin K cycle in liver: in coagulation cascade, activated clotting factors are indispensable for the formation of blood clot. (hindawi.com)
  • Since vitamin K epoxide reductase (VKOR) is responsible for the synthesis of reduced vitamin K, warfarin, by targeting at and inhibiting VKOR, can block the activation of clotting factors and decrease the blood clot [ 3 ]. (hindawi.com)
  • Interactions occur through a variety of mechanisms, including interference with warfarin metabolism, displacement from protein binding sites and disturbances of vitamin K absorption or metabolism. (aafp.org)
  • The bottom line of this report is that those with the "resistant" genotype (GG) who typically require a higher dose of warfarin show the greatest fall in the INR (or require the largest upward dose adjustment of warfarin) when daily vitamin K supplementation (150 mcg) is initiated to help stabilize the INR. (clotcare.com)
  • On the other hand, those who are more sensitive to warfarin (GA and AA genotype), show less of a change - or no change - in the INR with daily vitamin K supplementation. (clotcare.com)
  • Although a variety of other factors may influence the response to vitamin K supplementation, the mean increase in warfarin dose that was required was 25% for resistant (GG) patients, 8% for GA patients, and 0% for sensitive AA patients following the implementation of daily vitamin K supplementation. (clotcare.com)
  • Therefore, the warfarin-resistant "GG patients" can better utilize - or regenerate - whatever vitamin K is available while the more warfarin sensitive "AA patients" apparently can not "utilize" the additional vitamin K as well. (clotcare.com)
  • The warfarin doses before vitamin K were not significantly different between the 3 groups and, in fact, the absolute mean dose was lower in the GG group than in the GA or the AA group (3.23 mg, 4.52 mg, and 3.50 mg, respectively). (clotcare.com)
  • The warfarin doses after the addition of vitamin K also were not significantly different (mean daily doses of 4.05 mg, 4.86 mg, and 3.50 mg for GG, GA, and AA, respectively) - and the mean dose for the "resistant" group remained lower than the mean dose for the "average" (GA) group. (clotcare.com)
CYP2C91
  • Several CYP2C9 gene polymorphisms decrease the activity of the CYP2C9 enzyme and slow the body's metabolism of warfarin. (medlineplus.gov)
Efficacy2
  • Hyperthyroid and hypothyroid states alter warfarin efficacy. (aafp.org)
  • However, a direct comparison of ximelagatran and warfarin based on efficacy of the drugs, inconveniences in laboratory monitoring (INR, ALAT) and costs, is warranted, before any conclusion can be drawn as to the drug of choice in long-term prevention of venous thromboembolism. (escardio.org)
Stroke2
  • For those with end-stage renal failure (eGFR less than or equal to 15), death, heart attack and stroke happened in 53 percent in the warfarin group versus 66 percent in the non-warfarin group. (rxwiki.com)
  • A total of 548 consecutive stroke patients receiving IV recombinant tissue plasminogen activator (rtPA) were prospectively evaluated and details about warfarin pretreatment were carefully recorded. (neurology.org)
Commonly2
  • Dosing of warfarin is complicated because it is known to interact with many commonly used medications and certain foods. (wikipedia.org)
  • However, warfarin dosing is complicated by the fact that it interacts with many commonly used medications and even chemicals in some foods. (news-medical.net)
Major Bleeds2
  • Of these, 38 patients (4.4%) had major bleeds that required hospitalization: gastrointestinal bleeding from any source with or without a transfusion, and retroperitoneal or intracranial bleeding warranting discontinuation of warfarin treatment. (medscape.com)
  • Cite this: Major Bleeds on Warfarin More Likely as BMI Rises: Analysis - Medscape - May 08, 2015. (medscape.com)
Mechanism4
  • Prevention of clotting in arteries is usually undertaken with antiplatelet drugs, which act by a different mechanism from warfarin (which normally has no effect on platelet function). (wikipedia.org)
  • The general mechanism of herb-warfarin interaction almost remains unknown, yet several pharmacokinetic and pharmacodynamic factors were estimated to influence the effectiveness of warfarin. (hindawi.com)
  • The mechanism may be that thyroxine increases the affinity of warfarin for receptor sites in the liver, leading to decreased production of clotting factors. (aafp.org)
  • Given the proposed mechanism, one would expect all SSRIs to interact similarly with warfarin. (pharmacytimes.com)
Doses of warfarin2
  • A group led by Dr. Haifeng M. Wu of the Ohio State University has developed a new rapid method to genotype SNPs that will help clinicians to choose appropriate doses of warfarin for individual patients. (news-medical.net)
  • Yang et al suggest that 'on-site application of this method in hospital laboratories will greatly help clinicians to determine appropriate doses of warfarin to treat patients with thromboembolic disorders. (news-medical.net)
Rare complication1
  • Spontaneous lingual and sublingual haematoma: a rare complication of warfarin use. (pneumotox.com)
Response to warfarin5
  • Demirkan and colleagues reviewed the literature to study the effects of concurrent disease on response to warfarin. (aafp.org)
  • A MEDLINE search was performed to identify prospective trials, case reports and retrospective studies of the effects of various disease states on response to warfarin. (aafp.org)
  • The authors found that the effects of liver disease, hyperthyroidism and hypothyroidism on the response to warfarin are well documented in the literature. (aafp.org)
  • A severe coagulation defect and an exaggerated response to warfarin has been documented in patients with liver failure. (aafp.org)
  • The authors conclude that hepatic and thyroid diseases are well documented as disorders that can alter the response to warfarin. (aafp.org)
Therapy with warfarin4
  • For patients with a bileaflet mechanical valve or a Medtronic Hall (Minneapolis, MN) tilting disk valve in the aortic position who are in sinus rhythm and without left atrial enlargement, therapy with warfarin to a target INR of 2.5 (range, 2 to 3) is recommended. (druglib.com)
  • For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, therapy with warfarin to a target INR of 3 (range, 2.5 to3.5) is recommended. (druglib.com)
  • For patients with caged ball or caged disk valves, therapy with warfarin to a target INR of 3 (range, 2.5 to3.5) is recommended. (druglib.com)
  • For patients with a bioprosthetic valve in the mitral position, therapy with warfarin to a target INR of 2.5 (range, 2 to 3) for the first 3 months after valve insertion is recommended. (druglib.com)
Metabolism of warfarin1
  • Many genes are involved in the metabolism of warfarin and in determining the drug's effects in the body. (medlineplus.gov)
Complication1
  • PROTECT AF trial showed noninferiority of LAAC to warfarin but noted high procedural complication rates. (the-hospitalist.org)
Sodium4
  • Warfarin sodium tablets, USP have no direct effect on an established thrombus, nor does it reverse ischemic tissue damage. (druglib.com)
  • The dosage and administration of warfarin sodium must be individualized for each patient according to the patient's INR response to the drug. (druglib.com)
  • The following is a price list for the purchase of Warfarin Sodium 3mg from our online pharmacy. (federaldrugs.com)
  • To buy Warfarin Sodium 3mg online at these discount Warfarin Sodium prices simply click the "Add to Cart" button and follow the easy and secure checkout process. (federaldrugs.com)
Toxicity3
  • Warfarin (war' far in) was discovered after identification of the hemorrhagic activity that caused toxicity and bleeding in cattle after eating spoiled, sweet clover silage. (nih.gov)
  • Overdose of the oral anticoagulant warfarin (Coumadin), or drug interactions with warfarin, can lead to toxicity. (medscape.com)
  • Warfarin has moderate acute toxicity. (janusinfo.se)
Prothrombin3
  • The effects of warfarin are typically monitored by checking prothrombin time (INR) every one to four weeks. (wikipedia.org)
  • Warfarin interferes with the ability of prothrombin and clotting factors to form a clot. (medicalnewstoday.com)
  • Patients on warfarin might need to reduce their anticoagulant dose or monitor their prothrombin time more closely while taking atovaquone-proguanil, although coadministration of these drugs is not contraindicated. (cdc.gov)
Thrombus3
  • Warfarin is used to decrease the tendency for thrombosis, or as secondary prophylaxis (prevention of further episodes) in those individuals who have already formed a blood clot (thrombus). (wikipedia.org)
  • Warfarin treatment can help prevent formation of future blood clots and help reduce the risk of embolism (migration of a thrombus to a spot where it blocks blood supply to a vital organ). (wikipedia.org)
  • For high-risk patients with MI (e.g., those with a large anterior MI, those with significant heart failure, those with intracardiac thrombus visible on transthoracic echocardiography, those with AF, and those with a history of a thromboembolic event), therapy with combined moderate-intensity (INR, 2 to 3) warfarin plus low-dose aspirin (≤ 100 mg/day) for at least 3 months after the MI is recommended. (druglib.com)
Take warfarin1
Bleeding Risk3
  • Higher Warfarin Dose in Obesity, Higher Bleeding Risk? (medscape.com)
  • Do Antidepressants Increase Warfarin Bleeding Risk? (pharmacytimes.com)
  • More study is needed to assess whether or not mirtazapine increases bleeding risk when combined with warfarin. (pharmacytimes.com)
Versus warfarin1
  • Thromboembolic and Major Bleeding Events With Rivaroxaban Versus Warfarin Use in a Real-World Setting. (bvsalud.org)
Predict1
  • Nevertheless, the results suggest that body-mass index (BMI) may predict bleeding events in patients on warfarin. (medscape.com)
Embolism1
  • Long-term, low-intensity warfarin therapy for the prevention of recurrent venous thrombo-embolism. (escardio.org)
Analogues1
  • As a dual approach, we herein disclose electrochemical and mechanochemical methods for the efficient and straightforward synthesis of a new series of functionalized dihydrofuro[3,2- c ]chromenones using warfarin analogues. (rsc.org)
Prevention3
  • Oral ximelagatran is superior to placebo for extended prevention of venous thromboembolism in patients initially treated with warfarin (INR 2.0-3.0) for six months. (escardio.org)
  • Comparison of Low-intensity warfarin therapy with conventional-intensity warfarin therapy for long-term prevention of recurrent venous thromboembolism. (escardio.org)
  • The study included patients initiated on warfarin or rivaroxaban for thromboembolic prevention in nonvalvular AF between January 2012 and July 2016. (bvsalud.org)