This Figure shows the correlation between the plasma concentrations of dabigatran and its anticoagulant effect.  As can be seen, the INR does not change very much over 24 hours of plasma concentration values, and therefore the INR is not a reliable way to assess the presence and activity of dabigatran.  The other parameters, however – plasma concentrations and anticoagulation parameters – clearly peak within about 2 hours and return to almost baseline by 12 hours, which explains the reason for BID dosing with dabigatran.

 Reiffel JA. Am J Med 2013; 126: 00-00.