Surreptitious superwarfarin ingestion with brodifacoum.

Physicians must have a high index of suspicion when patients have unexplained prolongation of the prothrombin time and bleeding in the absence of detectable warfarin. Several common rodenticides contain modified versions of warfarin that are not detectable in standard warfarin assays. We present a case of surreptitious brodifacoum ingestion in a patient who had years of unexplained bleeding and negative warfarin levels.