Use of selective factor Xa inhibitors in special populations.

Many clinicians recommend long-term, postoperative thromboprophylaxis for patients who undergo major hip or knee replacement or hip fracture surgery. However, special care must be taken when administering pharmacoprophylaxis to such patients, as they commonly exhibit characteristics that are different from those of the general population and can affect their responses to certain drugs. Among the currently available thromboprophylactic agents are warfarin, the heparins, and the recently introduced selective factor Xa inhibitor, fondaparinux. One feature of fondaparinux is that it can be administered safely and efficaciously in a wide variety of patient populations, without the need for dosage modification.