Table 1

Principal mechanisms of action of drugs and associated PK/PD models

Reversible
 Simple direct effects
 Biophase distribution
 Slow receptor-binding
 Basic and extended indirect effects
 Signal transduction
Irreversible
 Cell or target inactivation
 Enzyme inactivation
 Signal transduction
Tolerance
 Counter-regulation
 Desensitization
 Up- or down-regulation
 Precursor pool depletion