SUPERWARFARIN POISONING: A SIGNIFICANT PUBLIC HEALTH PROBLEM

The newer rodenticides, so called "superwarfarins" or second generation Vitamin K-1 antagonists include brodifacoum, difenacoum, chlorphacinone, and bromodialone. They are characterized by profound anticoagulation with increased inhibition of Vitamin K dependent clotting factors and prolonged duration of effect. Whether accidental or intentional, poisoning with these compounds has been reported and appears to be increasing in frequency as these compounds have been popularly employed for warfarin-resistant rats. The American Association of Poison Control Centers reported 6116 exposures in 1992. We present three cases of brodifacoum ingestion with specific emphasis on chronic therapy and clinical management. Our experience is supported by a review of the literature which suggests that the ingestion of long acting second generation Vitamin K antagonists is seen surreptitiously in adults often presenting as suicides to a psychiatric service. In children, accidental exposure is most common. The unique presentation and treatment are important for the generalist to recognize. Ingestion of this kind is an important public health problem.