Determination of the in vivo Km and Vmax of a drug with tracer studies.
A method is described for determining the in vivo Km and Vmax values for a drug, utilizing a variant of the Michaelis-Menten equation and the elimination-rate constants of tracer doses of the drug administered at two different serum concentration values. The new method is the most accurate yet devised; unlike older methods, it is dependent on assumptions that generally are true and can be validated empirically. Application of the method is demonstrated by a study of phenytoin in humans.
Browne
T R
TR
Department of Neurology, Boston University School of Medicine, Massachusetts.
Greenblatt
D
D
Evans
J E
JE
Evans
B A
BA
Szabo
G K
GK
Schumacher
G E
GE
D006801:Humans; D008954:Models, Biological; D010599:Pharmacokinetics