A theoretical kinetic model describing the behavior of a receptor-enzy
me system during formation of drug addiction is considered in this art
icle. The model assumes concomitant action of narcotic on at least two
targets with opposite effects. Theoretical kinetic principles that th
e system must satisfy for the development of drug addiction are formul
ated. These kinetic principles are the slow inactivation of receptor-e
nzyme system and the divergence of characteristic times of dynamic con
centration of product and enzyme. (C) 1998 Elsevier Science Ireland Lt
d.