Warfarin Sodium: Uses, Dosage, Side Effects & Brands | MedexInfo
Warfarin Sodium
Rx
Generic NameWarfarin Sodium
Therapeutic ClassAnticoagulant (Vitamin K Antagonist)
Common Dose2–10 mg orally once daily (dose individualized)
PregnancyContraindicated
Indications ▼
Prevention and treatment of deep vein thrombosis (DVT)
Prevention and treatment of pulmonary embolism (PE)
Prevention of thromboembolic complications in atrial fibrillation
Prevention of thromboembolism in patients with mechanical heart valves
Management of myocardial infarction in selected cases
Mechanism & Pharmacokinetics ▼
Mechanism: Inhibits vitamin K epoxide reductase, reducing synthesis of vitamin K-dependent clotting factors II, VII, IX, and X; leads to anticoagulation.
Pharmacokinetics: Rapidly absorbed orally; peak plasma levels in 90 minutes. Highly protein-bound (>99%). Metabolized in liver via CYP2C9. Half-life 20–60 hours; excreted mainly in urine.
Dosage & Administration ▼
| Condition | Recommended Dose | Frequency |
|---|---|---|
| Prophylaxis of DVT/PE | 2–5 mg | Oral once daily |
| Treatment of DVT/PE | Initial 5–10 mg, adjusted by INR | Oral once daily |
| Atrial fibrillation / Mechanical valves | 2–10 mg, individualized | Oral once daily, monitor INR 2–3 |
Note: Monitor INR regularly; adjust dose to maintain therapeutic range. Avoid sudden dietary vitamin K changes.
Side Effects ▼
Bleeding (minor or major)
Bruising, hematoma
Gastrointestinal upset
Rare: skin necrosis, purple toe syndrome, alopecia
Hypersensitivity reactions (rare)
Contraindications ▼
Pregnancy (especially first trimester)
Active bleeding or bleeding disorders
Severe hepatic or renal impairment
Hypersensitivity to warfarin
Recent surgery with high bleeding risk
Drug Interaction ▼
NSAIDs, antiplatelets: increase bleeding risk
Antibiotics: may alter INR
Vitamin K supplements: reduce efficacy
Amiodarone, azoles, fluoroquinolones: alter metabolism, may increase INR
Pregnancy & Lactation ▼
Contraindicated in pregnancy (Category X)
Excreted in breast milk in small amounts; avoid breastfeeding or monitor infant
Clinical / Research Summary ▼
Therapeutic Role: Effective oral anticoagulant for prevention and treatment of thromboembolic events.
Clinical Effectiveness: Reduces risk of stroke, DVT, PE, and valve-related thromboembolism when INR is maintained in therapeutic range.
Safety Profile: Requires regular monitoring; risk of bleeding is primary concern. Adjust dose with co-medications or dietary changes.
Current Research: Focus on individualized dosing algorithms, warfarin vs direct oral anticoagulants, and bleeding risk reduction.
Patient Counseling Points ▼
Take at the same time daily; do not skip doses.
Monitor INR regularly; adjust dose as instructed.
Avoid sudden changes in diet rich in vitamin K (green leafy vegetables).
Report any unusual bleeding, bruising, or dark stools immediately.
Inform all healthcare providers about warfarin use.
Storage & Handling ▼
Store at 20–25°C, protect from moisture and light
Keep out of reach of children
Brand Names (Bangladesh & Global) ▼
Medical Disclaimer: This information is intended for educational purposes only and must not replace professional medical advice.
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