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Resource in Medication updated 7 Nov 2014

After a heart attack, John Smith was prescribed warfarin to stop harmful blood clots forming. But he wasn't confident with the knowledge he had about managing his medication and didn't realise the importance of going for regular blood tests.

An important part of John's treatment was the international normalised ratio (INR) test, to check the effect of the warfarin on his blood's clotting time. John's INR test showed a result of 11; his normal ideal result was around 3.

John ended up in intensive care with dangerously low oxygen and blood pressure, and a life-threatening pulmonary haemmorhage.

John made a full recovery and now feels in control of his warfarin programme.