- Subject has a history of hepatic impairment (characterized by prolonged prothrombin time/low concentrations of albumin) and/or renal insufficiency (subjects with an estimated CrCl ≤ 30 mL/min by Cockroft-Gault must be excluded). CrCL = [140-ageCr][weight/70] x 0.85 (if female); Cr in mg/dL; Weight in kg