Pesticide resistance in wild mammals--mechanisms of anticoagulant resistance in wild rodents.

Warfarin is commonly used worldwide as a rodenticide. It inhibits coagulation of blood by inhibiting vitamin K 2,3-epoxide reductase (VKOR) activity. An inadequate supply of vitamin K blocks the production of prothrombin and causes hemorrhage.

Elevated warfarin metabolism in warfarin-resistant roof rats (Rattus rattus) in Tokyo.

Wild roof rats (Rattus rattus) live in proximity to human habitats, and they may carry numerous pathogens of infectious diseases. Pest control is important for public health, and warfarin is a commonly used rodenticide worldwide. However, continual use of warfarin may cause drug resistance in rodents and lead to failure of their control, especially in urbanized areas.