SUPERWARFARIN POISONING

Background: Superwarfarin sodium exposure or poisoning is a growing pu blic health problem. There were 5133 reported cases of superwarfarin e xposure and poisoning in 1988 and 13 423 cases in 1995. Cases may be a ssociated with accidental exposure, suicide attempts, or Munchausen sy ndrome, and may be difficult to diagnose. Patients and Methods: Patien ts from northern Wisconsin with superwarfarin exposure or poisoning we re examined at a tertiary referral center in rural Wisconsin to determ ine what led to their exposure and to review the clinical manifestatio ns, diagnosis, treatment, and prevention of superwarfarin poisoning. R esults: Eleven cases satisfied the criteria for superwarfarin exposure or poisoning. All 7 children included in the study had accidentally i ngested superwarfarin, 2 adults had Munchausen syndrome, and 1 teenage r and 1 adult had attempted suicide using superwarfarin. Nine of the 1 1 cases had taken brodifacoum. The patients who had accidentally inges ted superwarfarin or attempted suicide using it were easily diagnosed, while diagnosis was markedly delayed for the 2 patients with Munchaus en syndrome. Full reversal of anticoagulation was quickly achieved in the cases of accidental ingestion and attempted suicide. We examined a nd treated the patients with Munchausen syndrome for months before est ablishing a diagnosis and fully reversing the anticoagulation. None of the patients in our study died of superwarfarin poisoning. Conclusion s: Superwarfarin exposure or poisoning is a growing public health prob lem that should be part of the differential diagnosis of patients who present with a coagulopathy consistent with vitamin K deficiency in th e absence of coumadin therapy, liver disease, or the use of an inhibit or, and whose conditions do not resolve with large doses of parenteral vitamin K-1 therapy.