Constant Pharmacologic Effect and Chronopharmacology: Theoretical Aspects

The theoretical drug infusion rates requisite to obtain a constant pharmacologic effect are determined taking into account chronopharmacologic phenomena. The introduction of chronopharmacology into pharmacokinetic theory leads to a clocktime-dependent infusion rate. The infusion modulation depends both on type of chronophenomenon, chronopharmacokinetics or chronestesy, and plasma clearance rate of the drug. In the presence of chronestesy of a biosystem the pharmacologic effect can be maintained constant only when plasma drug clearance is fast enough to allow an adequate modulation of the plasma drug concentration. Although the established equations proceed from theoretical concept they could be useful for programming drug delivery systems.