COUMADIN® is indicated for:

• Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism (PE).
• Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation (AF) and/or cardiac valve replacement.
• Reduction in the risk of death, recurrent myocardial infarction (MI), and thromboembolic events such as stroke or systemic embolization after myocardial infarction.

Limitations of Use

COUMADIN has no direct effect on an established thrombus, nor does it reverse ischemic tissue damage. Once a thrombus has occurred, however, the goals of anticoagulant treatment are to prevent further extension of the formed clot and to prevent secondary thromboembolic complications that may result in serious and possibly fatal sequelae.

COUMADIN is a vitamin K antagonist indicated for:

• Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism (1)
• Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation and/or cardiac valve replacement (1)
• Reduction in the risk of death, recurrent myocardial infarction, and thromboembolic events such as stroke or systemic embolization after myocardial infarction (1)

Limitation of Use

COUMADIN has no direct effect on an established thrombus, nor does it reverse ischemic tissue damage. (1)

• Individualize dosing regimen for each patient, and adjust based on INR response. (2.1, 2.2)
• Knowledge of genotype can inform initial dose selection. (2.3)
• Monitoring: Obtain daily INR determinations upon initiation until stable in the therapeutic range. Obtain subsequent INR determinations every 1 to 4 weeks. (2.4)
• Review conversion instructions from other anticoagulants. (2.8)

The dosage and administration of COUMADIN must be individualized for each patient according to the patient’s INR response to the drug. Adjust the dose based on the patient’s INR and the condition being treated. Consult the latest evidence-based clinical practice guidelines from the American College of Chest Physicians (ACCP) to assist in the determination of the duration and intensity of anticoagulation with COUMADIN [see References (15) ].

An INR of greater than 4.0 appears to provide no additional therapeutic benefit in most patients and is associated with a higher risk of bleeding.

Adjust the warfarin dose to maintain a target INR of 2.5 (INR range, 2.0-3.0) for all treatment durations. The duration of treatment is based on the indication as follows:

• For patients with a DVT or PE secondary to a transient (reversible) risk factor, treatment with warfarin for 3 months is recommended.
• For patients with an unprovoked DVT or PE, treatment with warfarin is recommended for at least 3 months. After 3 months of therapy, evaluate the risk-benefit ratio of long-term treatment for the individual patient.
• For patients with two episodes of unprovoked DVT or PE, long-term treatment with warfarin is recommended. For a patient receiving long-term anticoagulant treatment, periodically reassess the risk-benefit ratio of continuing such treatment in the individual patient.

In patients with non-valvular AF, anticoagulate with warfarin to target INR of 2.5 (range, 2.0-3.0).

• 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.
• 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.
• For patients with AF and mitral stenosis, long-term anticoagulation with warfarin is recommended.
• For patients with AF and prosthetic heart valves, long-term anticoagulation with warfarin is recommended; the target INR may be increased and aspirin added depending on valve type and position, and on patient factors.

• 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, 2.0-3.0) is recommended.
• For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, therapy with warfarin to a target INR of 3.0 (range, 2.5-3.5) is recommended.
• For patients with caged ball or caged disk valves, therapy with warfarin to a target INR of 3.0 (range, 2.5-3.5) is recommended.
• For patients with a bioprosthetic valve in the mitral position, therapy with warfarin to a target INR of 2.5 (range, 2.0-3.0) for the first 3 months after valve insertion is recommended. If additional risk factors for thromboembolism are present (AF, previous thromboembolism, left ventricular dysfunction), a target INR of 2.5 (range, 2.0-3.0) is recommended.

• 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, 2.0-3.0) warfarin plus low-dose aspirin (≤100 mg/day) for at least 3 months after the MI is recommended.

Oral anticoagulation therapy with warfarin has not been fully evaluated by clinical trials in patients with valvular disease associated with AF, patients with mitral stenosis, and patients with recurrent systemic embolism of unknown etiology. However, a moderate dose regimen (INR 2.0-3.0) may be used for these patients.

The appropriate initial dosing of COUMADIN varies widely for different patients. Not all factors responsible for warfarin dose variability are known, and the initial dose is influenced by:

• Clinical factors including age, race, body weight, sex, concomitant medications, and comorbidities
• Genetic factors (CYP2C9 and VKORC1 genotypes) [see Clinical Pharmacology (12.5) ]

Select the initial dose based on the expected maintenance dose, taking into account the above factors. Modify this dose based on consideration of patient-specific clinical factors. Consider lower initial and maintenance doses for elderly and/or debilitated patients and in Asian patients [see Use in Specific Populations (8.5) and Clinical Pharmacology (12.3) ]. Routine use of loading doses is not recommended as this practice may increase hemorrhagic and other complications and does not offer more rapid protection against clot formation.

Individualize the duration of therapy for each patient. In general, anticoagulant therapy should be continued until the danger of thrombosis and embolism has passed [see Dosage and Administration (2.2) ].

If the patient’s CYP2C9 and VKORC1 genotypes are not known, the initial dose of COUMADIN is usually 2 to 5 mg once daily. Determine each patient’s dosing needs by close monitoring of the INR response and consideration of the indication being treated. Typical maintenance doses are 2 to 10 mg once daily.

Table 1 displays three ranges of expected maintenance COUMADIN doses observed in subgroups of patients having different combinations of CYP2C9 and VKORC1 gene variants [see Clinical Pharmacology (12.5) ]. If the patient’s CYP2C9 and/or VKORC1 genotype are known, consider these ranges in choosing the initial dose. Patients with CYP2C9 *1/*3, *2/*2, *2/*3, and *3/*3 may require more prolonged time (>2 to 4 weeks) to achieve maximum INR effect for a given dosage regimen than patients without these CYP variants.

COUMADIN is a narrow therapeutic range (index) drug, and its action may be affected by factors such as other drugs and dietary vitamin K. Therefore, anticoagulation must be carefully monitored during COUMADIN therapy. Determine the INR daily after the administration of the initial dose until INR results stabilize in the therapeutic range. After stabilization, maintain dosing within the therapeutic range by performing periodic INRs. The frequency of performing INR should be based on the clinical situation but generally acceptable intervals for INR determinations are 1 to 4 weeks. Perform additional INR tests when other warfarin products are interchanged with COUMADIN, as well as whenever other medications are initiated, discontinued, or taken irregularly. Heparin, a common concomitant drug, increases the INR [see Dosage and Administration (2.8) and Drug Interactions (7) ].

Determinations of whole blood clotting and bleeding times are not effective measures for monitoring of COUMADIN therapy.

The anticoagulant effect of COUMADIN persists beyond 24 hours. If a patient misses a dose of COUMADIN at the intended time of day, the patient should take the dose as soon as possible on the same day. The patient should not double the dose the next day to make up for a missed dose.

The intravenous dose of COUMADIN is the same as the oral dose. After reconstitution, COUMADIN for injection should be administered as a slow bolus injection into a peripheral vein over 1 to 2 minutes. COUMADIN for injection is not recommended for intramuscular administration.

Reconstitute the vial with 2.7 mL of Sterile Water for Injection. The resulting yield is 2.5 mL of a 2 mg per mL solution (5 mg total). Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration. Do not use if particulate matter or discoloration is noted.

After reconstitution, COUMADIN for injection is stable for 4 hours at room temperature. It does not contain any antimicrobial preservative and, thus, care must be taken to assure the sterility of the prepared solution. The vial is for single use only, and any unused solution should be discarded.

Some dental or surgical procedures may necessitate the interruption or change in the dose of COUMADIN therapy. Consider the benefits and risks when discontinuing COUMADIN even for a short period of time. Determine the INR immediately prior to any dental or surgical procedure. In patients undergoing minimally invasive procedures who must be anticoagulated prior to, during, or immediately following these procedures, adjusting the dosage of COUMADIN to maintain the INR at the low end of the therapeutic range may safely allow for continued anticoagulation.

Since the full anticoagulant effect of COUMADIN is not achieved for several days, heparin is preferred for initial rapid anticoagulation. During initial therapy with COUMADIN, the interference with heparin anticoagulation is of minimal clinical significance. Conversion to COUMADIN may begin concomitantly with heparin therapy or may be delayed 3 to 6 days. To ensure therapeutic anticoagulation, continue full dose heparin therapy and overlap COUMADIN therapy with heparin for 4 to 5 days and until COUMADIN has produced the desired therapeutic response as determined by INR, at which point heparin may be discontinued.

As heparin may affect the INR, patients receiving both heparin and COUMADIN should have INR monitoring at least:

• 5 hours after the last intravenous bolus dose of heparin, or
• 4 hours after cessation of a continuous intravenous infusion of heparin, or
• 24 hours after the last subcutaneous heparin injection.

COUMADIN may increase the activated partial thromboplastin time (aPTT) test, even in the absence of heparin. A severe elevation (>50 seconds) in aPTT with an INR in the desired range has been identified as an indication of increased risk of postoperative hemorrhage.

Consult the labeling of other anticoagulants for instructions on conversion to COUMADIN.

• Pregnancy

COUMADIN is contraindicated in women who are pregnant except in pregnant women with mechanical heart valves, who are at high risk of thromboembolism [see Warnings and Precautions (5.5) and Use in Specific Populations (8.1) ]. COUMADIN can cause fetal harm when administered to a pregnant woman. COUMADIN exposure during pregnancy causes a recognized pattern of major congenital malformations (warfarin embryopathy and fetotoxicity), fatal fetal hemorrhage, and an increased risk of spontaneous abortion and fetal mortality. If COUMADIN is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus [see Warnings and Precautions (5.6) and Use in Specific Populations (8.1) ].

• Hemorrhagic tendencies or blood dyscrasias
• Recent or contemplated surgery of the central nervous system or eye, or traumatic surgery resulting in large open surfaces [see Warnings and Precautions (5.7) ]
• Bleeding tendencies associated with:
  • –Active ulceration or overt bleeding of the gastrointestinal, genitourinary, or respiratory tract
  • –Central nervous system hemorrhage
  • –Cerebral aneurysms, dissecting aorta
  • –Pericarditis and pericardial effusions
  • –Bacterial endocarditis
• Threatened abortion, eclampsia, and preeclampsia
• Unsupervised patients with conditions associated with potential high level of non-compliance
• Spinal puncture and other diagnostic or therapeutic procedures with potential for uncontrollable bleeding
• Hypersensitivity to warfarin or to any other components of this product (e.g., anaphylaxis) [see Adverse Reactions (6) ]
• Major regional or lumbar block anesthesia
• Malignant hypertension

• Pregnancy, except in women with mechanical heart valves (4)
• Hemorrhagic tendencies or blood dyscrasias (4)
• Recent or contemplated surgery of the central nervous system (CNS) or eye, or traumatic surgery resulting in large open surfaces (4, 5.7)
• Bleeding tendencies associated with certain conditions (4)
• Threatened abortion, eclampsia, and preeclampsia (4)
• Unsupervised patients with potential high levels of non-compliance (4)
• Spinal puncture and other diagnostic or therapeutic procedures with potential for uncontrollable bleeding (4)
• Hypersensitivity to warfarin or any component of the product (4)
• Major regional or lumbar block anesthesia (4)
• Malignant hypertension (4)

• Tissue necrosis: Necrosis or gangrene of skin or other tissues can occur, with severe cases requiring debridement or amputation. Discontinue COUMADIN and consider alternative anticoagulants if necessary. (5.2)
• Systemic atheroemboli and cholesterol microemboli: Some cases have progressed to necrosis or death. Discontinue COUMADIN if such emboli occur. (5.3)
• Heparin-induced thrombocytopenia (HIT): Initial therapy with COUMADIN in HIT has resulted in cases of amputation and death. COUMADIN may be considered after platelet count has normalized. (5.4)
• Pregnant women with mechanical heart valves: COUMADIN may cause fetal harm; however, the benefits may outweigh the risks. (5.5)

COUMADIN can cause major or fatal bleeding. Bleeding is more likely to occur within the first month. Risk factors for bleeding include high intensity of anticoagulation (INR >4.0), age greater than or equal to 65, history of highly variable INRs, history of gastrointestinal bleeding, hypertension, cerebrovascular disease, anemia, malignancy, trauma, renal impairment, certain genetic factors [see Clinical Pharmacology (12.5) ], certain concomitant drugs [see Drug Interactions (7) ], and long duration of warfarin therapy.

Perform regular monitoring of INR in all treated patients. Those at high risk of bleeding may benefit from more frequent INR monitoring, careful dose adjustment to desired INR, and a shortest duration of therapy appropriate for the clinical condition. However, maintenance of INR in the therapeutic range does not eliminate the risk of bleeding.

Drugs, dietary changes, and other factors affect INR levels achieved with COUMADIN therapy. Perform more frequent INR monitoring when starting or stopping other drugs, including botanicals, or when changing dosages of other drugs [see Drug Interactions (7) ].

Instruct patients about prevention measures to minimize risk of bleeding and to report signs and symptoms of bleeding [see Patient Counseling Information (17) ].

Necrosis and/or gangrene of skin and other tissues is an uncommon but serious risk (<0.1%). Necrosis may be associated with local thrombosis and usually appears within a few days of the start of COUMADIN therapy. In severe cases of necrosis, treatment through debridement or amputation of the affected tissue, limb, breast, or penis has been reported.

Careful clinical evaluation is required to determine whether necrosis is caused by an underlying disease. Although various treatments have been attempted, no treatment for necrosis has been considered uniformly effective. Discontinue COUMADIN therapy if necrosis occurs. Consider alternative drugs if continued anticoagulation therapy is necessary.

Anticoagulation therapy with COUMADIN may enhance the release of atheromatous plaque emboli. Systemic atheroemboli and cholesterol microemboli can present with a variety of signs and symptoms depending on the site of embolization. The most commonly involved visceral organs are the kidneys followed by the pancreas, spleen, and liver. Some cases have progressed to necrosis or death. A distinct syndrome resulting from microemboli to the feet is known as “purple toes syndrome.” Discontinue COUMADIN therapy if such phenomena are observed. Consider alternative drugs if continued anticoagulation therapy is necessary.

Do not use COUMADIN as initial therapy in patients with heparin-induced thrombocytopenia (HIT) and with heparin-induced thrombocytopenia with thrombosis syndrome (HITTS). Cases of limb ischemia, necrosis, and gangrene have occurred in patients with HIT and HITTS when heparin treatment was discontinued and warfarin therapy was started or continued. In some patients, sequelae have included amputation of the involved area and/or death. Treatment with COUMADIN may be considered after the platelet count has normalized.

COUMADIN can cause fetal harm when administered to a pregnant woman. While COUMADIN is contraindicated during pregnancy, the potential benefits of using COUMADIN may outweigh the risks for pregnant women with mechanical heart valves at high risk of thromboembolism. In those individual situations, the decision to initiate or continue COUMADIN should be reviewed with the patient, taking into consideration the specific risks and benefits pertaining to the individual patient’s medical situation, as well as the most current medical guidelines. COUMADIN exposure during pregnancy causes a recognized pattern of major congenital malformations (warfarin embryopathy and fetotoxicity), fatal fetal hemorrhage, and an increased risk of spontaneous abortion and fetal mortality. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus [see Use in Specific Populations (8.1) ].

COUMADIN exposure during pregnancy can cause pregnancy loss, birth defects, or fetal death. Discuss pregnancy planning with females of reproductive potential who are on COUMADIN therapy [see Contraindications (4) and Use in Specific Populations (8.8) ].

In the following clinical settings, the risks of COUMADIN therapy may be increased:

• Moderate to severe hepatic impairment
• Infectious diseases or disturbances of intestinal flora (e.g., sprue, antibiotic therapy)
• Use of an indwelling catheter
• Severe to moderate hypertension
• Deficiency in protein C-mediated anticoagulant response: COUMADIN reduces the synthesis of the naturally occurring anticoagulants, protein C and protein S. Hereditary or acquired deficiencies of protein C or its cofactor, protein S, have been associated with tissue necrosis following warfarin administration. Concomitant anticoagulation therapy with heparin for 5 to 7 days during initiation of therapy with COUMADIN may minimize the incidence of tissue necrosis in these patients.
• Eye surgery: In cataract surgery, COUMADIN use was associated with a significant increase in minor complications of sharp needle and local anesthesia block but not associated with potentially sight-threatening operative hemorrhagic complications. As COUMADIN cessation or reduction may lead to serious thromboembolic complications, the decision to discontinue COUMADIN before a relatively less invasive and complex eye surgery, such as lens surgery, should be based upon the risks of anticoagulant therapy weighed against the benefits.
• Polycythemia vera
• Vasculitis
• Diabetes mellitus

The following factors may be responsible for increased INR response: diarrhea, hepatic disorders, poor nutritional state, steatorrhea, or vitamin K deficiency.

The following factors may be responsible for decreased INR response: increased vitamin K intake or hereditary warfarin resistance.

The following serious adverse reactions to COUMADIN are discussed in greater detail in other sections of the labeling:

• Hemorrhage [see Boxed Warning , Warnings and Precautions (5.1) , and Overdosage (10) ]
• Necrosis of skin and other tissues [see Warnings and Precautions (5.2) ]
• Systemic atheroemboli and cholesterol microemboli [see Warnings and Precautions (5.3) ]

Other adverse reactions to COUMADIN include:

• Immune system disorders: hypersensitivity/allergic reactions (including urticaria and anaphylactic reactions)
• Vascular disorders: vasculitis
• Hepatobiliary disorders: hepatitis, elevated liver enzymes. Cholestatic hepatitis has been associated with concomitant administration of COUMADIN and ticlopidine.
• Gastrointestinal disorders: nausea, vomiting, diarrhea, taste perversion, abdominal pain, flatulence, bloating
• Skin disorders: rash, dermatitis (including bullous eruptions), pruritus, alopecia
• Respiratory disorders: tracheal or tracheobronchial calcification
• General disorders: chills

Most common adverse reactions to COUMADIN are fatal and nonfatal hemorrhage from any tissue or organ. (6)

To report SUSPECTED ADVERSE REACTIONS, contact Bristol-Myers Squibb at 1-800-721-5072 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.