When is warfarin indicated

In most cases, warfarin can be initiated on day 1, after the first dose of the parenteral agent has been given. Warfarin should not be initiated alone, and the parenteral anticoagulant should not be discontinued until the INR is in the therapeutic range for two consecutive days. Depending on the patient's risk of thromboembolism and bleeding, bridging should occur when a patient's oral anticoagulation therapy needs to be interrupted eTable C.

Interruption is common in patients undergoing surgery. For most persons who are not having a minor procedure, warfarin will be stopped approximately five days before surgery and restarted 12 to 24 hours postoperatively. LMWH should be restarted approximately 24 hours after the procedure, and it may be prudent to wait 48 to 72 hours before resuming the medication for patients at high risk of bleeding or who are undergoing major surgery.

At least 1 of the following: Aortic valve prosthesis caged-ball ortilting-disk. Dental: continue warfarin with an oral prohemostatic agent or stop warfarin2 to 3 days before procedure. Aortic valve prosthesis bileaflet and atleast 1 of the following: age older than75 years; atrial fibrillation; congestiveheart failure; diabetes mellitus;hypertension; prior stroke or TIA. Aortic valve prosthesis bileaflet withoutatrial fibrillation and no other stroke riskfactors.

Bleeding risk in hospitalized patients has been linked to multiple factors including active gastric or duodenal ulcer,bleeding within 3 months before admission, and thrombocytopenia. Outpatient management of anticoagulation therapy. Am Fam Physician. Douketis JD. Perioperative management of patients who are receiving warfarin therapy: an evidence-based and practical approach. Kaatz S, Paje D.

Update in bridging anticoagulation. For all warfarin indications, perioperative bridging is not indicated in patients at low risk of thromboembolism. The effectiveness of warfarin is well-established; however, it is a suboptimal anticoagulant because it requires frequent monitoring and dosage adjustments, and because of its potential for multiple drug-drug, drug-food, and drug—disease state interactions. It has a lengthy half-life and a delayed anticoagulant effect, and it often requires bridging therapy.

Since the approval of warfarin in , no other oral option existed for patients who needed long-term anticoagulation therapy. This changed in with the U. Characteristics of these anticoagulants are provided in Tables 4 and 5. FDA boxed warning: increased risk of stroke in patients with nonvalvular atrial fibrillation who discontinue apixaban without adequate continuous anticoagulation. Contraindications: active pathological bleeding; history of serious hypersensitivity reaction to apixaban.

Use not recommended in patients with prosthetic heart valves or severe hepatic impairment; pregnant or breastfeeding patients. Contraindications: active pathological bleeding; history of serious hypersensitivity reaction to dabigatran; mechanical prosthetic heart valve.

Use not recommended in patients with bioprosthetic heart valves; pregnant or breastfeeding patients. Contraindications: active pathological bleeding; history of severe hypersensitivity reaction to rivaroxaban. Reduce risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. John's wort. Increased bleeding risk with certain medications e. Note differences in recommendation for dosage adjustments in renal impairment based on indication.

Avoid if moderate Child-Pugh class B or severe Child-Pugh class C hepatic impairment or with any hepatic disease associated with coagulopathy. Refer to package labeling for information on conversion from or to warfarin Coumadin or parenteral anticoagulants, and on intervention for surgery. Do not chew, break, open capsules; capsules must be dispensed in original container and not repackaged because of sensitivity to moisture. Refer to package labeling for information on conversion from or to warfarin or parenteral anticoagulants, and on intervention for surgery.

Recommended duration of therapy is 12 days for total knee replacement and 35 days for total hip replacement. When transitioning from warfarin to rivaroxaban, give first dose of rivaroxaban when the international normalized ratio is less than 3. Food and Drug Administration. Other P-glycoprotein inhibitors should be evaluated on an individual basis. Information from references 10 through At least as effective and possibly superior at reducing total venous thromboembolism without increasing major bleeding risk.

Food and Drug Administration boxed warning for increased risk of thrombotic events when apixaban discontinued in patients with nonvalvular atrial fibrillation. Food and Drug Administration boxed warning for increased risk of thrombotic events when rivaroxaban discontinued in patients with nonvalvular atrial fibrillation.

By alleviating the need for frequent dose titrations and laboratory monitoring, especially with therapy initiation and new drug additions or deletions, apixaban possesses key clinical advantages compared with warfarin. Warfarin's predictable adverse effect profile, once-daily administration, reversibility with vitamin K, and ability to be monitored for sub-and supratherapeutic dosing provide reassurance for the clinician.

By alleviating the need for frequent dose titrations and laboratory monitoring, especially with therapy initiation and new drug additions or deletions, dabigatran possesses key clinical advantages compared with warfarin. Warfarin's predictable adverse effect profile, once-daily administration, reversibility with vitamin K, and ability to be monitored for sub- and supratherapeutic dosing provide reassurance for the clinician. By alleviating the need for frequent dose titrations and laboratory monitoring, especially with therapy initiation and new drug additions or deletions, rivaroxaban possesses key clinical advantages compared with warfarin.

Warfarin's predictable adverse effect profile, once-daily administration, relatively longer half-life, reversibility with vitamin K, and ability to be monitored for sub- and supratherapeutic dosing provide reassurance for the clinician.

Oral administration makes it easier to allow for longer duration of deep venous thrombosis prophylaxis in patients undergoing orthopedic surgery. Dabigatran is available as a fixed-dose medication for the prevention of systemic embolism and stroke in patients with nonvalvular atrial fibrillation.

Without applicable laboratory monitoring, there is no mechanism to establish if a patient's INR is subtherapeutic or supratherapeutic. If the patient's INR is supratherapeutic, there is no antidote for reversal.

This can be problematic when determining the appropriate management in a patient who needs emergent surgery. The short half-life is potentially challenging when assessing the impact of noncompliance or missing the second daily dose.

Limited data are available for patients with hepatic impairment and for patients who are obese. Thus, it is not acceptable to automatically consider all patients taking warfarin to be good candidates for dabigatran.

Adverse effects of dabigatran, mg twice daily, compared with warfarin include dyspepsia Dabigatran's safety profile needs further evaluation. Elevated transaminase levels in the Randomized Evaluation of Long-term Anticoagulation Therapy trial were comparable to those seen with warfarin, and routine liver function test monitoring is not recommended.

Rivaroxaban is indicated for prevention of deep venous thrombosis in patients undergoing knee or hip replacement surgery, for treatment of deep venous thrombosis and pulmonary embolism, for reducing the risk of recurrent deep venous thrombosis and pulmonary embolism after initial treatment, and for prevention of systemic embolism in patients with nonvalvular atrial fibrillation.

It is expected to prolong the activated partial thromboplastin time and increase anti—factor Xa levels; however, the usefulness of monitoring has not been established. In four trials evaluating the role of rivaroxaban in the prevention of VTE in patients undergoing orthopedic surgery, rivaroxaban significantly reduced the primary outcome total VTE and all-cause mortality compared with enoxaparin, without significantly increasing bleeding risk.

Rivaroxaban has been studied for the treatment of acute coronary syndromes. Similar to dabigatran, baseline and periodic renal function monitoring are recommended. Similar to dabigatran, apixaban is also indicated for the prevention of systemic embolism and stroke in patients with nonvalvular atrial fibrillation.

There were also lower mortality rates in the apixaban group in both trials and a lower major bleeding rate in the apixaban group compared with warfarin in the ARISTOTLE trial.

Five oral direct factor Xa inhibitors i. Point-of-care monitors are typically used in primary care and anticoagulation clinics and have several advantages, including rapid INR acquisition and interpretation. These monitors make it possible for patients to check their INRs at home, which is referred to as patient self-testing. Reassuring data exist for the effective use of patient self-testing in selected patients who demonstrate monitor competency.

Decreased mortality, enhanced INR control, decreased thromboembolic events, and an improvement in patient satisfaction and quality of life have been demonstrated with patient self-testing, all without an increase in bleeding complications. The cost of patient self-testing, which is similar to the cost of newer oral anticoagulants, can be significant without reimbursement; however, self-testing is not appropriate for all patients on warfarin therapy 22 — 24 eTable D.

Centers for Medicare and Medicaid Services coverage includes patients:. Taking warfarin Coumadin for long-term anticoagulation for venousthromboembolism, mechanical heart valves, or atrial fibrillation.

Patients who may not be good self-testing candidates include those:. With language barriers that cannot be overcome with the assistance of a familymember. Patient self-testing is areliable and acceptable alternative to laboratory INR monitoring.

Br J Haematol. Effect of home testing of international normalized ratio on clinical events[published correction appears in N Engl J Med. N Engl J Med. Self-monitoring and self-managementof oral anticoagulation.

Cochrane Database Syst Rev. CMS Manual System. Pub Medicare claims processing. Accessed August 29, Data Sources: A PubMed search was completed in Clinical Queries using the key terms outpatient, anticoagulation, warfarin, dabigatran, rivaroxaban, heparin, low-molecular-weight heparin, dalteparin, enoxaparin, patient self-monitor, and INR. The search included meta-analyses, randomized controlled trials, clinical trials, clinical guidelines, and reviews. Search date: August 10, Already a member or subscriber?

Log in. Interested in AAFP membership? Learn more. Winkle College of Pharmacy, and a clinical pharmacist in the outpatient anticoagulation clinic at West Chester Ohio Hospital. Winkle College of Pharmacy, and a clinical pharmacist in the outpatient anticoagulation clinic at West Chester Hospital.

Winkle College of Pharmacy, Eden Ave. Reprints are not available from the authors. Health care expenditures and therapeutic outcomes of a pharmacist-managed anticoagulation service versus usual medical care. Comparison of two different models of anticoagulation management services with usual medical care. Warfarin maintenance dosing patterns in clinical practice: implications for safer anticoagulation in the elderly population.

University of Michigan. Cardiovascular Center. Anticoagulation management service for health professionals. Warfarin dose adjustment. Accessed September 23, Ebell MH. Evidence-based adjustment of warfarin Coumadin doses. Eliquis apixaban tablets for oral use [prescribing information] Princeton N. Accessed January 23, Pradaxa dabigatran etexilate mesylate capsules for oral use [prescribing information]. Ridgefield, Conn. Xarelto rivaroxaban tablets, for oral use [prescribing information].

Titusville, N. Accessed December 30, Dabigatran versus warfarin in patients with atrial fibrillation [published correction appears in N Engl J Med. Secondary prevention in non-rheumatic atrial fibrillation after transient ischaemic attack or minor stroke. Lancet ;— General consensus has been reached regarding the recommendations for anticoagulation in patients with rheumatic AF.

However, until recently, clear-cut recommendations have not been available for management of patients with nonvalvular AF. Since , many large, prospective, randomized trials have been conducted to evaluate the risks and benefits of warfarin Coumadin or aspirin therapy in the prevention of stroke.

The results of these trials provide a strong foundation for recommendations regarding the use of anticoagulation therapy in patients with nonvalvular AF.

The risk factors for stroke in these patients included a history of hypertension 67 percent , congestive heart failure 44 percent , diabetes 19 percent , myocardial infarction 19 percent and a mean left atrial size of 4. After approximately one year of follow-up, the trial was prematurely stopped because the stroke rate in the aspirin plus low-dose warfarin group was substantially higher than that in the warfarin group 7. The advantage of full-dose warfarin INR: 2.

The rate of stroke in this subgroup was 3. In patients without a previous stroke, the rate of stroke was 1. The data clearly favor anticoagulation with warfarin to an intended INR of 2. In hemodynamically compromised patients, AF must be treated emergently with synchronized electric cardioversion. There are no controlled studies available to suggest recommendations regarding anticoagulation in these patients.

In a nonrandomized trial of patients instances of cardioversion , 20 the incidence of an embolic event was 0. These results are impressive because the number of patients with congestive heart failure, hypertension and rheumatic heart disease was greater in the anticoagulation group than in the group not receiving anticoagulation. The prevalence of intracardiac thrombi in patients with AF has been investigated in several studies.

In all but one patient, the thrombi were located in the atrial appendage. In another study, 24 left atrial thrombi were detected by transesophageal echocardiography in 13 percent of patients with no acute embolic event, even though AF had been present for fewer than three days. In patients with AF of three days' duration or longer and no embolic event, the prevalence of left atrial thrombi was 29 percent. Based on these observations, it is generally recommended that anticoagulation be instituted for three weeks before cardioversion is attempted in patients with AF of more than two days' duration.

To minimize thromboembolic complications, anticoagulants should be continued for four weeks after cardioversion. This period is required for recovery of atrial mechanical contractility after conversion to a sinus rhythm. Such a recommendation is based more on tradition and theory than on findings from controlled trials. The time required for a clot to form in the atrium during AF is unknown.

Once a clot is formed, the assumption is that a poorly adherent clot is more likely to dislodge at the time of cardioversion. It has been estimated that the time needed for organization of the newly formed clot is approximately two weeks. Therefore, anticoagulation for four weeks following cardioversion would cover the time required for organization of a clot, adherence of any existing clot and prevention of a new clot.

Continued anticoagulation after cardioversion would theoretically protect the patient from embolic events until atrial mechanical activity is restored, which can take up to two weeks.

An alternate approach using transesophageal echocardiography has been suggested for use in hospitalized patients with AF of more than 48 hours' duration. Patients without atrial thrombi underwent electrical or pharmacologic cardioversion, followed by warfarin therapy for four weeks after cardioversion. No clinical embolic events occurred in this group. Patients with atrial thrombi identified on transesophageal echocardiography received warfarin therapy for three weeks before cardioversion was attempted and for four weeks after cardioversion.

The need for anticoagulation before cardioversion in patients with AF of short duration less than 48 hours is less clear. These patients can harbor left atrial thrombi and systemic emboli. Intravenous administration of heparin before cardioversion, followed by warfarin therapy for four weeks after cardioversion, may be beneficial but supportive data are not available. In pooled data from five randomized trials mean age of patients was 69 years , the rate of intracranial hemorrhage in warfarin-treated patients therapeutic target range varied was 0.

One explanation for the higher rate of intracranial hemorrhage in this elderly subgroup is that the selection of patients for enrollment was less restrictive than that used in the five trials. Elderly patients overall would be expected to have a rate of warfarin-associated intracranial hemorrhage higher than 0.

In addition to increasing age of the patient, the strongest risk factors for warfarin-associated intracranial hemorrhage are poorly controlled hypertension, excessive anticoagulation and a history of cerebrovascular disease. Anticoagulation with warfarin INR: 2. Information from references 26 and Patients with lone AF who are under 60 years of age with no other risk factors for stroke are at low risk for systemic embolism and stroke.

The risks of anticoagulation in these patients outweigh the potential benefits. Patients over 60 years of age are at intermediate risk of stroke and will benefit from anticoagulation. Younger patients without heart failure or cardiac chamber dilatation who are at high risk for atherosclerosis may take aspirin in a dosage of mg per day.

A decision to initiate anticoagulation must be individualized, with the physician carefully weighing the risk of bleeding against the potential reduction in embolic risks. Current recommendations for antithrombotic therapy for AF necessitate individualization of therapy after an integrated clinical assessment that evaluates thromboembolic risk due to AF alone, other potential indications for anticoagulation, hemorrhagic risk and nonmedical factors related to compliance, the patient's ability to follow through with INR monitoring, the patient's gait stability, the risk of other trauma and the patient's preferences.

Already a member or subscriber? Log in. Interested in AAFP membership? Learn more. He formerly was a clinical instructor of medicine and a fellow in cardiology at East Carolina University School of Medicine, Greenville, N.

Akhtar completed a residency in internal medicine at St. Mary's Hospital, University of Rochester N. School of Medicine and Dentistry. Reeves received a medical degree from the University of Texas Medical Branch at Galveston and completed a residency in internal medicine at Montefiore Hospital, Pittsburgh, Pa. Address correspondence to Waheed Akhtar, M. Reprints are not available from the authors.

Epidemiology and mechanism of atrial fibrillation and atrial flutter. Am J Cardiol. Management of atrial fibrillation in adults: prevention of thromboembolism and symptomatic treatment. Mayo Clin Proc. Epidemiologic assessment of chronic atrial fibrillation and risk of stroke: the Framingham study.

Pai SM, Torres V. Atrial fibrillation: new management strategies. Curr Probl Cardiol. Prevalence of abnormalities of electrocardiogram in old people. Br Heart J. Because no 2 patients are exactly alike, and recommendations can vary from 1 person to another, it is important to seek guidance from a provider who is familiar with your individual condition.

Written by American Heart Association editorial staff and reviewed by science and medicine advisers. See our editorial policies and staff. About Arrhythmia. Why Arrhythmia Matters. Understand Your Risk for Arrhythmia. Symptoms, Diagnosis and Monitoring of Arrhythmia. Prevention and Treatment. Arrhythmia Tools and Resources. How Does Warfarin Work? Monitoring and Dosing Tips The goal of warfarin therapy is to decrease the clotting tendency of blood, not to prevent clotting completely.

Difference Between Brand-Name and Generic Medications Generic drugs are supposed to have the same dosage, therapeutic effects, route of administration, side effects, and strength as the original drug.

Warfarin must be taken exactly as prescribed. Signs of unusual bleeding include: bleeding from the gums, blood in the urine, bloody or dark stool, a nosebleed, or vomiting blood.

When to Call Your Healthcare Provider If you experience the following signs of bleeding, you should call or your healthcare provider immediately: Severe headache, confusion, weakness or numbness Coughing up large amounts of bright red blood Vomiting blood Bleeding that will not stop Bright red blood in stool Fall or injury to the head Headache that is severe or unusual Some simple changes to decrease the risk of bleeding while taking warfarin include the following: Use a soft-bristle toothbrush Floss with waxed floss rather than unwaxed floss Shave with an electric razor rather than a blade Take care when using sharp objects, such as knives and scissors Avoid activities that have a risk of falling or injury e.

Pregnancy Warfarin is not recommended during pregnancy. Travel Check with your healthcare provider if you expect to travel. Never double a dose because you missed a dose. Do tell your healthcare provider when you get sick or hurt. Do take warfarin exactly as prescribed. Do tell anyone giving you medical or dental care that you are taking warfarin.

Do keep appointments for blood tests. Warfarin Interacts With Other Medications Patients who take warfarin should consult with their healthcare provider before taking any new medication, including over-the-counter nonprescription drugs, herbal medicines, vitamins or any other products.

Patients undergoing warfarin therapy should avoid drinking alcohol on a daily basis. Alcohol should be limited to no more than 1 to 2 servings of alcohol occasionally.

This means an average of one to two drinks per day for men and one drink per day for women. A drink is one 12 oz. The antiplatelet effect of alcohol increases the risk of major bleeding, even if the INR remains within the target range. Foods - Some foods can interfere with the effectiveness of warfarin. The most important point to remember is to eat what you normally eat and not to make any major changes in your diet without contacting your healthcare provider.