Superwarfarin intoxication: two case reports and review of pathophysiology and patient management

Superwarfarin vitamin K antagonists are found in rat poisons and are readily available. Pediatric exposures are common but are usually asymptomatic without significant coagulopathy. Superwarfarin intoxication must be considered in any adult who presents with an unexplained coagulopathy with extreme elevation of prothrombin time and partial thromboplastin time with associated depletion of vitamin K dependent factors. If superwarfarin toxicity is confirmed, intentional ingestion should be considered, as a large quantity of ingested rat poison is necessary to induce a coagulopathy. Patients with superwarfin induced coagulopathy require several months of high dose oral and parenteral vitamin K supplementation. We describe two patients with superwarfarin toxicity treated at Louisiana State University Health in Shreveport and review pathophysiology and patient management.