[Relations between pharmacokinetics and effectiveness of ACE inhibitors]

While being similar to each other with respect to their pharmacodynamic effects, the various ACE inhibitors may differ considerably concerning their pharmacokinetic properties. Pharmacokinetic features that may influence the clinical choice for or against a particular ACE inhibitor include its oral bioavailability, plasma protein binding, tissue distribution, metabolization, and excretion. It should be kept in mind, however, that there may be considerable discrepancies between pharmacokinetic parameters in the plasma and the clinical effects (e.g., on blood pressure) of the same substance. These differences may be due to the fact that ACE inhibitors, especially upon chronic administration, predominantly act on local (paracrine/intracrine) renin-angiotensin-systems (RAS) rather than on the plasma RAS (endocrine RAS).