Superwarfarin

Superwarfarin is a term for highly potent anticoagulant rodenticides, comprising second-generation anticoagulant rodenticides (SGARs) such as brodifacoum, bromadiolone, difenacoum, and difethialone. These compounds are designed to kill rodents by causing sustained bleeding and are more potent and longer lasting than warfarin. They are used in pest control and are not approved for human consumption.

They inhibit the vitamin K cycle by blocking vitamin K epoxide reductase (VKORC1), preventing activation of vitamin K–dependent clotting factors II, VII, IX, and X, as well as proteins C and S. The result is coagulopathy that may develop days to weeks after exposure because of long tissue persistence and slow release from fat and liver stores.

Exposure occurs through ingestion of bait or contaminated food, or accidental contact with treated materials. Symptoms include unexplained bruising, nosebleeds, gum bleeding, and, in severe cases, intracranial hemorrhage. Diagnosis relies on a prolonged INR and a compatible exposure history.

Treatment involves removing ongoing exposure and giving vitamin K1 for an extended period, with INR monitoring. In severe bleeds, rapid reversal with fresh frozen plasma or prothrombin complex concentrates may be used alongside vitamin K.

Because of potency and persistence, SGARs are tightly regulated in many countries. They pose risks to pets and wildlife, and accidental or deliberate ingestion can require prolonged management due to late-onset coagulopathy.