Dr. Rishal Rahman P: WARFARIN – Balancing Clot Prevention With Safe Monitoring
Dr. Rishal Rahman P, Clinical Pharmacist Intern at Aster MIMS Kottakkal, posted on LinkedIn:
”Day 14: WARFARIN – Balancing Clot Prevention with Safe Monitoring
Indications
Prevention and treatment of venous thromboembolism (VTE, DVT, PE)
Prevention of stroke/systemic embolism in atrial fibrillation
Prosthetic heart valve thromboprophylaxis
Secondary prevention after myocardial infarction
Mechanism of Action
Inhibits Vitamin K epoxide reductase complex (VKORC1) → prevents activation of clotting factors II, VII, IX, X and proteins C & S → ↓ coagulation.
Dosage
Initial: 2–5 mg/day orally
Maintenance: 2–10 mg/day (adjust per INR)
Target INR:
2.0–3.0 for most indications
2.5–3.5 for mechanical prosthetic valves
Clinical Pharmacist Tips
Monitor INR regularly (every 2–4 weeks once stable).
Maintain consistent dietary vitamin K intake (avoid sudden ↑/↓ in green leafy vegetables).
Strong drug–drug & food interactions → always check before prescribing.
Educate patients about bleeding signs (bruising, gum bleed, black stools).
Contraindications
Pregnancy (teratogenic)
Active bleeding, recent major surgery, hemorrhagic stroke
Severe uncontrolled hypertension
Poor compliance for monitoring
Drug Interactions
Increased effect (↑ bleeding risk): Antibiotics (e.g., metronidazole, TMP-SMX), amiodarone, antifungals, SSRIs
Decreased effect (↓ anticoagulation): Rifampin, carbamazepine, barbiturates, vitamin K-rich foods
NSAIDs, aspirin → ↑ bleeding risk (even without INR changes)
Adverse Drug Reactions (ADR)
Bleeding (most common, dose-dependent)
Skin necrosis (rare, usually within 3–10 days, esp. in protein C/S deficiency)
Purple toe syndrome
Teratogenicity (nasal hypoplasia, stippled epiphyses)”

Stay informed with Hemostasis Today.
-
Aug 28, 2026, 15:10Ify Osunkwo: Strengthening Sickle Cell Care Systems at Global Conference in Nairobi
-
Aug 28, 2026, 15:08Muhammed Safvan: One Drop of Blood Can Tell a Story
-
Aug 28, 2026, 14:52Jessica Lee: Standing Together for Children and Families with Bleeding Disorders
-
Aug 28, 2026, 14:45Daisy Souster: A New Chapter in Bleeding Disorder Advocacy
-
Aug 28, 2026, 14:42Oluwatoyin Iyabode Ajayi: Heavy Periods – When Is Menstrual Bleeding Too Much?
-
Aug 28, 2026, 14:20Alyson Reidy: Factor Man and Community Support Take Center Stage at NBDF 2026
-
Aug 28, 2026, 14:09New Study Highlights Pregnancy Challenges in Inherited Bleeding Disorders – Glanzmann’s Research Foundation
-
Aug 28, 2026, 13:55Swatee C: A Guide to Common Uterine Disorders
-
Aug 28, 2026, 12:14Gathoni Kungu: Run to End Postpartum Hemorrhage and Save Lives