Warfarin

Warfarin sodium tablets are 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 Warfarin sodium tablets have no direct effect on an established thrombus, nor does it reverse ischemic tissue damage. …

• Individualize dosing regimen for each patient, and adjust based on INR response
• Knowledge of genotype can inform initial dose selection
• Monitoring: Obtain daily INR determinations upon initiation until stable in the therapeutic range
• Obtain subsequent INR determinations every 1 to 4 weeks
• Review conversion instructions from other anticoagulants
• Individualized Dosing The dosage and administration of warfarin sodium tablets must be individualized for each patient according to the patient’s International Normalized Ratio (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 regarding the duration and intensity of anticoagulation for the indicated conditions
• Recommended Target INR Ranges and Durations for Individual Indications 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
• Venous Thromboembolism (including deep venous thrombosis [DVT] and PE) Adjust the warfarin dose to maintain a target INR of 2.5 (INR range, 2.0 to 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. …

Warfarin Sodium Tablets USP, 2 mg are supplied as lavender to light lavender, oval shaped uncoated scored tablets with debossing ‘762’ and ‘2’ on either side of the breakline on one side and ‘AN’ on the other side. Scored tablets: 2 mg (3)

• Advise the patient to read the FDA-approved patient labeling (Medication Guide)
• Instructions for Patients Advise patients to: Strictly adhere to the prescribed dosage schedule [see Dosage and Administration ]
• If the prescribed dose of warfarin sodium is missed, take the dose as soon as possible on the same day but do not take a double dose of warfarin sodium the next day to make up for missed doses [see Dosage and Administration ]
• Obtain prothrombin time tests and make regular visits to their physician or clinic to monitor therapy [see Dosage and Administration ] . …

• Warfarin sodium is contraindicated in: Pregnancy Warfarin sodium 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 and Use in Specific Populations ]
• Warfarin sodium can cause fetal harm when administered to a pregnant woman. …

Concomitant use of drugs that increase bleeding risk, antibiotics, antifungals, botanical (herbal) products, and inhibitors and inducers of CYP2C9, 1A2, or 3A4. ( 7 ) Consult labeling of all concurrently used drugs for complete information about interactions with warfarin sodium or increased risks for bleeding. (7) 7.1 General Information Drugs may interact with warfarin sodium through pharmacodynamic or pharmacokinetic mechanisms. …

Tissue necrosis: Necrosis or gangrene of skin or other tissues can occur, with severe cases requiring debridement or amputation. Discontinue warfarin sodium and consider alternative anticoagulants if necessary. (5.2) Calciphylaxis: Fatal and serious cases have occurred. Discontinue warfarin sodium and consider alternative anticoagulation therapy. ( 5.3 ) Acute kidney injury may occur during episodes of excessive anticoagulation and hematuria. ( 5.4 ) Systemic atheroemboli and cholesterol microemboli: Some cases have progressed to necrosis or death. Discontinue warfarin sodium if such emboli occur. …

The following serious adverse reactions to warfarin sodium are discussed in greater detail in other sections of the labeling: Hemorrhage [see Boxed Warning , Warnings and Precautions (5.1) , and Overdosage (10) ] Tissue Necrosis [see Warnings and Precautions (5.2) ] Calciphylaxis [see Warnings and Precautions (5.3) ] Acute Kidney Injury [see Warnings and Precautions (5.4) ] Systemic Atheroemboli and Cholesterol Microemboli [see Warnings and Precautions (5.5) ] Limb Ischemia, Necrosis, and Gangrene in Patients with HIT and HITTS [see Warnings and Precautions (5.6) ] Other Clinical Settings with Increased Risks [see Warnings and Precautions (5.8) ] Other adverse reactions to warfarin sodium in …

IN SPECIFIC POPULATIONS Pregnant women with mechanical heart valves: warfarin sodium may cause fetal harm; however, the benefits may outweigh the risks. ( 8.1 ) Lactation: Monitor breastfeeding infants for bruising or bleeding. ( 8.2 ) Renal Impairment: Instruct patients with renal impairment to frequently monitor their INR. …

10.1 Signs and Symptoms Bleeding (e.g., appearance of blood in stools or urine, hematuria, excessive menstrual bleeding, melena, petechiae, excessive bruising or persistent oozing from superficial injuries, unexplained fall in hemoglobin) is a manifestation of excessive anticoagulation. 10.2 Treatment The treatment of excessive anticoagulation is based on the level of the INR, the presence or absence of bleeding, and clinical circumstances. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.