title: Errors involved in instantaneous intravascular input assumptions.
abstract: A comparative evaluation of a zero-order input and the generally accepted instantaneous intravascular input assumption is made for two- and three-compartment open model systems. Equations are derived and a nomogram is prepared to calculate the magnitude of error involved in instantaneous input assumptions. It is suggested that all intravascular administrations be considered as zero-order inputs.
mesh_terms: D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D007700:Kinetics; D008954:Models, Biological; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D004364:Pharmaceutical Preparations