Contraceptive patch raises clot risk:

Women who use a contraceptive patch appear to be more than twice as likely to develop a dangerous blood clot in their veints as thhose who use an oral contraceptive, new research shows. Alexdender M Walker and colleagues,from i3 Drug Safety in Auburndale, Massachusetts, note that it was not known if users of the patch system ran the same risk of stroke, heart attack and venous blood clots as users of oral contraceptives. They point out that the FDA changed the labelling for the patch contraceptive system in 2005 to warn of a possible increased risk of socalled "thrombotic events," because of a higher average circulating estrogen levels with the product.