Warfarin toxicity. It’s causes, clinical presentation, sign and symptoms, management and complications. I also have discussed a case of Warfarin toxicity I recently saw in emergency department. Hope it helps!
2. What is Warfarin?
Warfarin is an anticoagulant drug.
It is prescribed for patients with chronic atrial fibrillation,
prosthetic heart valves, to prevent formation of blood
clots and strokes.
Warfarin requires regular blood testing and frequent
dosage adjustments as it is linked to increased bleeding
risk, which can be life threatening.
3. What is Warfarin Toxicity?
Warfarin toxicity happens when you have too much
warfarin in your blood.
It can occur because of certain changes in food or drugs
that can either increase the effect of warfarin or decrease
it’s metabolism or excretion.
It might occur if patient do not get his INR checked
regularly as this drug needs optimisation regularly based
on the INR.
4. Signs and Symptoms
Rashes/Bruises
Severe Headache/Dizziness
Heavy bleeding after injury/trauma
Hematuria, Hemoptysis
Melena, Hematemesis
Menorrhagea
Severe abdominal pain
5. Investigations
Coagulation Profile : PT, APTT, INR, Fibrinogen levels
CBC
Urine DR
Renal Function Tests –serum urea, creatinine and
electrolytes
Liver Function Tests
ECG
6. Management
Vitamin K –orally/intravenously
Blood products
Symptomatic
Treat the cause
8. Case I saw in ER
83 year old gentleman known case of
atrial fibrillation, on warfarin for the past
12 years presented in emergency
department with complaint of an episode
of black stool in morning.
9. Clinical approach
What questions to be asked in History?
General examination.
Systemic examination.
Differential diagnosis.
Investigations to order.
Management.
10. Specific questions to be asked in
History.
What was the actual color of the stool?
How many episodes since morning?
Have you ever had similar episode before?
Any associated blood in vomiting? (Hematemesis)
Blood in urine?/Brown/Pink/Red urine? (Hematuria)
Blood in cough/sputum? (Hemoptysis)
Last menstrual period? (If female patient)
Any associated headache/fever/cough/chest pain/loose
stool/vomiting/constipation/abdominal pain/dizziness/weakness/new
onset rash/numbness/tingling.
11. General examination
Vitals
Anemia/Jaundice
Dehydration
Rash/Bruises
Actively bleeding (in case of trauma/injury)
Sub conjuctival hemorrhages
Gum/Nasal bleed
Shortness of breath/Dyspnea
13. What I found in History
So, he had a single episode of black stool in the morning. And
that was tarry black in color, semi solid in consistency, average
amount.
Never had any prior history.
No history of hematemesis, hemoptysis, hematuria.
History of fever, cough and generalized body weakness
positive for the past 7 days. But no streak of blood noticed.
No associated abdominal pain/chest
pain/dysuria/dizziness/headache/gum bleed/nasal bleed.
14. On Examination
Average built gentleman, lying comfortably on bed, vitally
stable.
Dehydration +ve
GCS 15/15, well oriented with time, place and person.
Chest : bilateral basal occasional crackles.
CVS : no added heart sound.
Abdomen : soft, non tender
Per rectal : no active bleeding on inspection
DRE : positive for black stool
17. Management Plan in ED
Inj. Vitamin K (if deranged INR)
For Upper GI bleed :
Inj. Omeprazole 80 mg IV STAT
Start IV infusion of Omeprazole 8mg per hour.
Somatostatins
OTHERS :
Arrange blood products
Take Gastroenterology team on board for melena. (Actively
bleeding)
Take Cardiology team on board for medicine optimization.
