The topic is nicely reviewed here. Of greatest interest is rivaroxaban (Xarelto) as it is the only one among the novel oral anticoagulants approved for treatment of DVT and PE in the US. Although the review summarizes the usual pharmacology and labeling a nagging question concerning rivaroxaban remains: is it time to change practice and if so, how? Now when patients present with DVT or PE do we just give them a pill and call it a day?
That question warrants a close look at the EINSTEIN trials for DVT and PE. In both trials, patients in the rivaroxaban arm were usually pretreated with enoxaparin for a day or two prior to enrollment. So the question of treatment in the first 24 hours or so is not well studied. Second, patients in both trials were excluded if thrombolytic therapy was anticipated, whatever that meant. But it implies that the treatments have not been compared in the sickest of the sick patients. Remember too that the results show non-inferiority rather than superiority to standard treatment. Finally, there are all those pesky post-marketing reports that are sure to follow.
So putting aside for now cost and patient preference considerations what's a hospitalist to do? If you're prone to err on the side of caution you might want to go with the time tested regimens for at least the first 24 hours, particularly in the sicker patients.
I did look this up in UptoDate. At present, acknowledging that this may change, they are recommending traditional treatments (LWMH or UFH followed by VKA) over novel anticoatulants, for the entire treatment course due to more clinical experience with the former.