In the original studies for DOACs, three key populations were excluded, so we don’t have data for use in these patients. They are Obese patients, pregnant women, and cancer patients.
But many doctors like Chakrabarty and Bernstein routinely use Xarelto in obese patients regardless of their BMI. There are some articles that support that like this one (Ther Adv Cardiovasc Dis. 2016 Oct;10(5):294-303).
However, in June of 2016, the International Society of Hemostasis and Thrombosis (ISTH) published this (J Thromb Haemost. 2016 Jun;14(6):1308-13) review of literature recommending avoidance of DOACs in patients with BMIs greater than 40.
“Data are limited on the efficacy and toxicity of direct factor Xa inhibitors in obese individuals. Based on a 2016 review of available literature, the International Society of Hemostasis and Thrombosis (ISTH) recommends avoidance of these agents in individuals with a body mass index (BMI) >40 kg/m2, or weight ≥120 kg. They recommend the use of these agents at standard dose for patients with a BMI ≤40 kg/m2. This reflects our general practice, although it should not replace clinical judgment regarding avoidance in individuals with a lower BMI or use in those with a higher BMI. ” uptodate.com
References
J Thromb Haemost. 2016 Jun;14(6):1308-13. https://www.ncbi.nlm.nih.gov/pubmed?term=27299806. | http://onlinelibrary.wiley.com/doi/10.1111/jth.13323/full
https://www.uptodate.com/contents/direct-oral-anticoagulants-and-parenteral-direct-thrombin-inhibitors-dosing-and-adverse-effects
Ther Adv Cardiovasc Dis. 2016 Oct;10(5):294-303