Kidney function assessment and its role in drug development, review and utilization

A key regulatory requirement pertaining to drug development is characterization of the role of kidney function in drug disposition and response, along with provision of corresponding renal dose adjustment recommendations. Traditionally, this information has been derived from Phase I pharmacokinetic studies in which regulatory guidance exists for pharmaceutical manufacturers on the design, conduct, analysis, and interpretation of data. Categorization and stratification of subjects into kidney function groups and dosing recommendations have historically been based on creatinine clearance estimates using the Cockcroft-Gault equation. As new estimating equations have emerged, the choice of equation for assessment of kidney function has become an area of debate. This review highlights these equations and provides recent examples of the use of quantitative models, incorporating efficacy and safety to make rational dose recommendations in subjects with impaired kidney function.