Acute toxicity anticoagulant rodenticides

As a result of intensive research, derivatives of 4-hydroxycoumarin were found, which proved to be particularly efficient against rodents and resistant to anticoagulant rodenticides. Difenacoum (34) is a chronic rodenticide, which acts as a typical indirect blood anticoagulant similar to warfarin. However, it is effective against rats and mice, which are resistant to warfarin and other anticoagulant rodenticides, and is more toxic than warfarin to susceptible strains of these rodents. The chemical composition of difenacoum is 3-(3-p-biphenyl-1,2,3,4-tetrahydro-naphth-l-yI)-4-hydroxycoumarin. Its acute oral LD50 is 1.8 mg/kg for Norway rats (Hadler et al., 1975a,b). 

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