ABSTRACT
Pharmacodynamics (PD) and toxicodynamics (TD), while related to pharmacokinetics and toxicokinetics , are quite different from them. The target receptor occupancy has to be at a sufficient level to achieve the desired therapeutic effect in a large portion of the desired patient population but there must not be too much or excessive receptor occupancy. The target receptor occupancy has to be at a sufficient level to achieve the desired therapeutic effect in a large portion of the desired patient population but there must not be too much or excessive receptor occupancy. The use of relevant disease models has, of course, been the standard for understanding PD and has come back to active discussion for understanding TD. Disease models are commonly used to understand and “calibrate” therapeutic effects, and are increasingly used to avoid “discovering” adverse effects and the limits thereof only in patients.
