- Renal impairment (glomerular filtration rate [GFR] <45 mL/minute (min)/1.73 square meter (m^2) as calculated by the Modification of Diet in Renal Disease equation) calculated as follows: GFR (mL/min per 1.73 m^2) = 175*(standardized serum creatinine)^-1.154 * (age)^-0.203 * 1.212 (if black) * 0.742 (if female)