Interaction of antitumor agents in sarcoma 180 system

Abstract

Interaction of antitumor agents in activity and in toxicity was examined separately. Ascites sarcoma 180 and ddN mice were used as the tumor system. Interaction was evaluated on the concept of pharmacological synergism and not of therapeutic synergism. In activity, 18 out of 91 combinations provided synergism and most of them contained alkylating agents and antibiotics. Antitumor agents were therefore classified into 2 groups from the point of drug interaction. Synergism was observed in combinations of agents in Group I, alkylating agents, antibiotics, and alkaloids. In combination of agents in Group II (antimetabolites and others), additive action was observed. As a result, 18, 65, and 8 combinations provided synergism, additive action, and antagonism, respectively. On the other hand, in toxicity, 13, 27, and 38 out of 78 combinations provided synergism, additive action, and antagonism, respectively. The combination that provided synergism in activity and antagonism in toxicity were 8 out of 91 combinations tested. In general, fortunately, combinations of antitumor agents were more than additive in activity and less than additive in toxicity.