Which statement about Coumadin (warfarin) is accurate?

The accurate statement about Coumadin (warfarin) is that it is not recommended for pregnant and lactating women. This is due to warfarin's ability to cross the placenta and potentially cause fetal harm, including teratogenic effects during pregnancy. Additionally, warfarin can be excreted in breast milk, which poses risks to breastfeeding infants. Healthcare providers usually prescribe alternative anticoagulants that are considered safer for pregnant women, such as low molecular weight heparins.

The other statements are not applicable because warfarin acts as a vitamin K antagonist rather than a vitamin B antagonist, it does not require antithrombin as a cofactor for its anticoagulant effect, and it is monitored using the INR (International Normalized Ratio) rather than the APTT (Activated Partial Thromboplastin Time) test, which is more relevant for monitoring heparin therapy.