The new coumadin-killers, direct thrombin inhibitor dabigatran (approved in the U.S.) and direct factor Xa inhibitor rivaroxaban (coming soon) could usher in an awesome new era of anticoagulation, without warfarin's requirements of cumbersome monitoring and annoying in-hospital titrations.

But what happens when patients taking these drugs bleed, or need emergency surgery? Fresh-frozen plasma doesn't work. Novo-7 might work, but is ungodly expensive.

Eerenberg et al show in 12 healthy men that prothrombin complex concentrate rapidly and completely reversed the prothrombin time (PT) prolongation associated with rivaroxaban. But it did nothing to reverse dabigatran -- the drug that's currently approved in the U.S.

On the other hand, hemodialysis theoretically removes about 2/3 of circulating dabigatran (the remaining 1/3 is bound to plasma proteins). Nephrologists, start your pagers!

Eerenberg ES et al. Reversal of Rivaroxaban and Dabigatran by Prothrombin Complex Concentrate. A Randomized, Placebo-Controlled, Crossover Study in Healthy Subjects. Circulation 2011;124:1573-1579.