Abstract
The most important criteria for the evaluation of antibacterially active sulfonamides are presented. The chemically determined blood levels is by itself not a reliable measure of the chemotherapeutic efficacy. The various sulfonamides show considerable differences in physicochemicalproperties, degrees of acetylation and oxidation and protein-binding pattern. The importance of these factors is discussed. On the basis of the different pharmacokinetic properties, absorption and excretion patterns, it is suggested that the sulfonamides be classified into the 3 groups: short acting, medium-acting and long-acting.