ABSTRACT
This chapter focuses on the pharmacokinetic/pharmacodynamic (PK/PD) evaluation of receptor-mediated effects and side effects. It identifies optimized dosage regimens with improved risk benefit ratios. One problem is that in today’s educational system much emphasis is given to PK principles where dose-proportional changes in drug concentrations are very common. The ultimate goal of PK-PD modeling is to describe effect-time relationships and derive optimum dose recommendations. There are two characteristic parameters that can be derived easily to translate PK and PD data into a dose recommendation. The pulmonary and systemic effects of the given dose can then be easily calculated by substituting the relevant concentration terms into the Emax equation. Simulations not shown indicate that the shorter the dosing interval, the smaller the numerical value of the optimized dose but the higher the overall pulmonary effect and the difference between systemic and topical cumulative effects. Thus, the most pronounced lung targeting is observed with the frequent application of small doses.
