It was already know that Ortho Evra can cause blood clots. Now the maker of the patch is saying that overweight women using the patch are at a particularly high risk of developing blood clots. Janssen-Ortho Inc. (subsidiary of Johnson & Johnson) also warns that women should not expose the Ortho Evra patch to sources of heat such as saunas and whirlpools. The company believes there is a theoretical risk that doing so might cause an unintentional increase in estrogen exposure.
Janssen-Ortho Inc. is a Canadian manufacturer who markets Ortho Evra in the United States. These new warnings were endorsed by Health Canada, the Canadian agency responsible for ensuring the safety and effectiveness of pharmaceutical products in that country. No such precautions exist in the United States concerning heat exposure to the patch.