Prolonged coagulopathy after brodifacoum exposure.

PURPOSE: A case of brodifacoum exposure leading to coagulopathy lasting for approximately one year despite treatment with large doses of phytonadione is reported.
SUMMARY: A 36-year-old man was diagnosed with severe coagulopathy. He was treated and discharged on 40 mg of oral phytonadione daily. The cause of the coagulopathy remained unknown at discharge, but the hematologist theorized that exposure to a vitamin K antagonist was likely the source of the patient's condition. The patient was rehospitalized one week later with an International Normalized Ratio (INR) of 5.9 despite self-reported medication compliance. Oral phytonadione was increased to 80 mg daily. The patient was seen at an outpatient hematology clinic for several months and continued on tapering dosages of oral phytonadione. A coagulopathy panel from the original hospitalization confirmed the presence of brodifacoum, though the method of exposure remained unclear. He was lost to follow-up until approximately nine months later, when he reported taking 10 mg daily of oral phytonadione and had an INR of 1. Oral phytonadione was discontinued. Two months later, his INR was greater than 9, despite an undetectable level of brodifacoum. He was rehospitalized with oropharyngeal hematoma approximately 1 year after the initial coagulopathy diagnosis. The patient was discharged on 40 mg oral phytonadione daily with outpatient follow-up.
CONCLUSION: A patient with brodifacoum exposure ingested brodifacoum had coagulopathy that lasted approximately one year despite long-term treatment with large dosages of oral phytonadione. The coagulopathy persisted even when brodifacoum was undetectable in the serum. Long-term treatment with high-dose phytonadione is expensive, which may influence medication compliance.