Who should be tested

If you are taking warfarin, or other anti-coagulant, you should regularly test your blood to ensure the medication is working safely and effectively.
We can test your blood and give you an immediate INR value (see below).
Simply call into the pharmacy at any time.
There is NO charge for this service.

If you are on warfarin, or know someone who is, talk to them about our service.

The test

The standard device used to monitor the effects of warfarin gives a number called the International Normalised Ratio, or INR.
Essentially it checks how long it takes for the sample blood to clot, which it then reads as INR.

The test is gentle. Your blood is sampled with an almost pain-free finger prick. A result, your INR, is available within about 10 mins.

We will review this, advise on the dose and date of the next test, and print out a small dosing calendar for you to take away.

INR or International Normalised Ratio

Your INR (International Normalised Ratio) needs to stay within a certain range, called the target INR. This will be advised by your doctor, and may also vary from time to time.
For most people the target INR ranges from 2 to 3, however some people have a slightly lower or higher target INR.

If your INR is outside your target range

• If your INR is too high, your blood clots less effectively and the risk of bleeding increases.
  
• If your INR is too low, your blood is more likely to form a blood clot prematurely.
  

Monitoring your INR and keeping it in your target range will help you to avoid these side effects.

How often is a test needed?

When you first start taking warfarin your INR should be tested maybe every 1 - 2 days for the first week.
When you have stabilised on the warfarin dose that achieves your target INR maybe you need testing monthly.
Any changes to your diet or medicines may mean more frequent testing to check their effect on your INR.

What affects your INR

Many factors can affect how warfarin works in your body so it’s important to have your INR tests done when they are scheduled. This helps to make sure your INR stays within the target range.
Always talk to your doctor or pharmacist about how changes to your intake may affect your INR. These changes can be your:

• current medicines;
• new medicines;
• diet changes;
• alternative 'medicines'; or
  
• over-the-counter vitamins and minerals.

Other changes can occur if you are unwell or travelling, especially overseas.

More here.