Our February 2026 Quick Question was a quiz that drew 42 responses. The stem asked, “Which DOAC is a direct thrombin inhibitor?” Your answers:
- Apixaban: 9 (21%)
- Betrixaban: 0
- Dabigatran: 32 (76%)
- Edoxaban: 0
- Rivaroxaban: 1 (3%)
We performed well on this question. No one chose betrixaban, an FXa-directed oral anticoagulant that was withdrawn in the summer of 2020. Edoxaban (Savaysa®, Lixiana®), apixaban (Eliquis®), and rivaroxaban (Xarelto®) are also DOACs that suppress FXa. One clue is the presence of the letter X in each generic name. Dabigatran (Pradaxa®) was the first DOAC to be FDA-approved (2010), and is the only DOAC in general use that directly suppresses thrombin. See “Asundexian,” December 5, 2025, to learn of current efforts to develop direct anticoagulants that suppress FXIa. Since FXIa deficiency is associated with mild bleeding, it may be that an anti-FXIa anticoagulant introduces a lower bleeding risk than the current anticoagulants.
Still, not 100% or even over 80% correct. Dabigatran was one of the first DOACs to be approved and marketed (2010 by the US FDA), but is now the least prescribed DOAC. Apixaban, followed by rivaroxaban, are the most popular DOACs–probably why they ‘scored’ highly on the quiz. Best known!