The problem
A manufacturing problem could result in some tablets containing a higher dose than listed. Consuming a tablet with a higher than usual dose may result in abnormal bruising and/or bleeding, vomiting blood or with the appearance of coffee grounds, blood in the urine or stool, or black tarry stools.

Details
Marevan (warfarin) blue 3mg tablets supplied after 23 November 2009. Marevan is an anticoagulant treatment widely used to prevent blood clots.

What to do
You should not suddenly stop taking this medicine. However, you should have the tablets replaced and seek advice as soon as possible. Tablets can be exchanged at your pharmacy free-of-charge. Contact the doctor or clinic that prescribed the medicine for advice on whether further monitoring may be required. If you have suffered any ill effects you should see your doctor immediately.