Combination of Misonidazole and m-AMSA: Effects on Radiation Sensitivity and Toxicity in E. Coli

Summary

Simultaneous administration of misonidazole and m-AMSA resulted in additive radio-sensitization and toxicity in E. coli B/r. At low drug doses the toxicities may be super-additive. However, experiments in N₂ and O₂ indicated that a therapeutic benefit from the combination is unlikely. Depending upon the actual sequence and the presence of O₂, pretreatment by one drug could lead to enhancement or reduction of the toxicity of a subsequent exposure to the other drug. In particular, an m-AMSA pretreatment made the toxicity of misonidazole independent of the oxygen concentration. Possible implications of the interaction of the two chemicals are discussed.