The present disclosure provides novel methods for determining an effective dosage of a PAA prodrug and for treating a UCD that incorporate body surface area and urinary PAGN concentration. The disclosure further provides novel methods for assessing compliance with PAA prodrug administration that incorporate urinary PAGN concentration, and the subjects current dosing regimen, BSA, or age. The disclosure further provides novel methods of treating a UCD in a subject in need thereof that incorporate urinary PAGN concentration, and the subjects current dosing regimen, BSA, and/or age.
