A Pragmatic Approach to Superwarfarin Intoxication in a Resource Constraint Setting; a Case Report

Superwarfarins are highly lethal rodenticides which are much more potent than the warfarin owing to various structural changes in the parent compound that confers high half-life and increase affinity to vitamin K epoxide. We report a case of a 19 years old female who presented bleeding prolonged PT and APTT. Factor assay showed significantly lower levels vitamin K dependent coagulation factors. She was given conventional doses of FFP and vitamin K for two consecutive days, although she responded clinically but her coagulation profile failed to show any improvement. Hence superwarfarin poisoning was considered. Based on this assumption patient was cross questioned repeatedly, and subsequently she admitted that she had ingested rodenticide with the suicidal intent. Hence she was given higher doses of vitamin K and FFP for several days after which her PT and APTT shortened significantly. Superwarfarin toxicity clinically presents with bleeding and deranged coagulation profile. Differentiating it from other causes is challenging but very crucial, as it does not responds to usual doses of vitamin K and plasma. This case highlights the importance of maintaining high index of suspicion of superwarfarin toxicity in coagulopathy of unknown etiology that fails to respond to conventional doses of treatment. Detailed history with interrogation of leading questions in such cases is of integral importance.