[Dose finding in antibacterial chemotherapy (author's transl)]

The therapy of bacterial infections is considered against the background of the relations existing within the system bacteria-man-chemical substance. The experimental conditions and the difficulties are discussed which are encountered in the determination of in vitro values and their transfer into therapy. On this background the basic equation of chemotherapy is discussed. The factors are given which reduce the strict validity of this basic equation and lead to the introduction of a safety factor when making a dose proposal.