Patient Information

Education-focused information about Warfarin therapy, INR monitoring, and staying safe.

When to Seek Immediate Help

Call your healthcare provider or go to the nearest Emergency Room if you experience:

  • Persistent nausea, vomiting blood, or "coffee ground" vomit.
  • Headaches, dizziness, or weakness.
  • Nosebleeds that don't stop.
  • Dark red or brown urine.
  • Blood in bowel movements or dark, tarry stools.
  • A serious fall or head injury (even without symptoms).
  • Car accident or major injury.
  • Unusual bruising or "black and blue" skin.

What is Warfarin?

Warfarin is an anticoagulant medication, often called a "blood thinner." It helps prevent harmful blood clots from forming or growing larger. It is prescribed for conditions like atrial fibrillation, mechanical heart valves, or deep vein thrombosis (DVT).

Note: Warfarin does not dissolve existing clots, but it prevents them from getting bigger.

Understanding Your INR

The International Normalized Ratio (INR) measures how long it takes your blood to clot.

  • Target Range:Usually between 2.0 and 3.0 for most conditions. Your doctor will set your specific range.
  • Too Low:Risk of clots increases (blood is "too thick").
  • Too High:Risk of bleeding increases (blood is "too thin").

Taking Your Medication

  • Take Warfarin at the same time every day (usually in the evening).
  • Do not skip or double doses.
  • If you miss a dose by less than 8 hours, take it immediately. If more than 8 hours, wait for the next scheduled dose.
  • Use a pill box or calendar to track your doses.

Clinic Updates

  • INR Clinic Hours: Thu 5:00 PM – 8:00 PM, Fri 9:00 AM – 12:00 PM
  • Monthly education class: First Thursday of every month, 4:00 PM – 5:00 PM
  • Parking: Ample free parking available

Please contact the clinic for class details.

Clinic care room

Preparing for your visit

Regular monitoring is key to your safety.

Please arrive 10 minutes early and bring your OHIP card, medication list, and dosing calendar.

Lifestyle Tips

  • • Keep Vitamin K intake consistent (green leafy vegetables).
  • • Avoid alcohol or limit consumption.
  • • Tell us about ANY new medications or supplements.