The selectivity of cytostatic action depends of the following factors:
a) the compound, its mode of action, the applied dosage, the localization and the speed of activation, its metabolites and excretion;
b) the sensitivity or resistance of the proliferated tissue;
c) the individual general condition of the patient, the degree of malnutrition, the integrity of defense mechanisms and the ability of detoxication and the regenerative capacity of hemopoiesis.
The action of cytostatic agents directed against specific cell functions of different cell systems develops distinct differences in clinical effects and toxicity among alkylating agents, antimetabolites and mitotic inhibitors. Comparative data of these compounds are given. Due to its selectivity of action each cytostatic agent possesses a specific optimal indication in hemoblastoses, neoplasias or immune reactions.