Dose discordance of direct acting oral anticoagulants using different equations for estimating GFR: a literature review

INTRODUCTION: Direct oral anticoagulants (DOACs) are widely prescribed nowadays. Available DOACs are renally eliminated to some extent and need dose adjustment in patients with kidney dysfunction. Cockcroft-Gault (CG) formula has been used to estimate creatinine clearance in DOACs trials. Nowadays, Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) are preferred equations for estimating glomerular filtration rate (GFR). We reviewed studies that simulated DOACs dosing in patients with atrial fibrillation by MDRD, CKD-EPI, and CG. AREAS COVERED: DOACs dose discordance varies from 28.8% underdosing to 59.2% overdosing when MDRD or CKD-EPI equations are substituted for CG. MDRD and CKD-EPI overestimate the GFR in lower thresholds of kidney function especially in elderly and females and result in overestimation of DOACs dosing or misclassifying the patients to be eligible for receiving DOACs when they are contraindicated. Compared with CG, MDRD and CKD-EPI underestimate the level of kidney function in higher GFR extremes and in these patients suggest DOACs when they are not recommended or suggest lower doses. EXPERT OPINION: Until running large clinical studies on efficacy/safety of DOACs dosing using MDRD or CKD-EPI equations, use of CG method for DOACs dosing is recommended in real practice.