The blood thinning drug Marevan (warfarin) has been recalled after concerns some tablets may contain a higher dose than labelled. Manufacturer GlaxoSmithKline says the 28 January 2010 recall is only for the blue 3mg tablets (batch 35222), in circulation since 23 November 2009, due to a manufacturing problem. Marevan is an anticoagulant widely used to help prevent blood clots. Overdose can lead to bruising, abnormal bleeding, vomiting with blood or a ‘coffee grounds’ appearance, blood in the urine or stool or black tarry stools. Brown 1mg and pink 5mg tablets are not part of the recall. Anyone using medicine from the affected 3mg batch should continue taking it but seek advice as soon as possible from their doctor and return the Marevan to their pharmacy for a free replacement. GSK New Zealand advises people to contact their doctor immediately if any ill effects are noticed. "Patient safety is our first concern and the results of our investigations to date give us confidence that this is an isolated incident. If patients have any concerns about their medication, they should discuss these with their pharmacist or health practitioner,” says Geoff McDonald, General Manager at GSK New Zealand. The Pharmacy Guild of New Zealand urges the 10% of warfarin consumers using this 3mg dose to consult their pharmacist. “Community pharmacists are more than willing to step up and help during this problem,” says Annabel Young, CEO of the Guild.