bromfenacoum and Hemoperitoneum

Five horses originating from 4 different California race tracks were submitted to the California Animal Health and Food Safety Laboratory for necropsy and diagnostic workup. The 5 horses had a history of sudden collapse and death during exercise. In all of them, massive hemoperitoneum and hemorrhages in other cavities or organs were observed. The liver from these 5 animals and from 27 horses that had been euthanized due to catastrophic leg injuries (controls) were subjected to a rodenticide anticoagulant screen. Traces of brodifacoum, diphacinone, or bromadiolone were detected in the 5 horses with massive bleeding (5/5), and no traces of rodenticides were detected in control horses (0/27). Other frequent causes of massive hemorrhages in horses were ruled out in 4 of the cases; one of the horses had a pelvic fracture. Although only traces of anticoagulants were found in the livers of these horses and the role of these substances in the massive bleeding remains uncertain, it is speculated that exercise-related increases in blood pressure may have reduced the threshold for toxicity of these anticoagulants.

Topics: 4-Hydroxycoumarins; Animals; Anticoagulants; California; Hemoperitoneum; Hemorrhage; Horse Diseases; Horses; Liver; Male; Phenindione; Physical Conditioning, Animal; Rodenticides

We report a case of brodifacoum (superwarfarin) intoxication of unknown etiology presenting as hemoperitoneum after fluconazole administration for one week before the onset of symptoms. The initial prothrombin time (PT) and partial thromboplastin time (PTT) were markedly prolonged, although a mixing study with normal plasma showed that the corrected PT and PTT were in the normal range. Vitamin K-dependent coagulation factors (Factors II (5%), VII (8%), IX (4%), and X (6%)), and Protein C (16%) and Protein S (19%) activities were reduced. Although the patient denied ingesting rodenticides or medications other than an antifungal drug, fluconazole, superwarfarin toxicity was suspected; subsequently, his serum brodifacoum level was found to be positive. After administration of fresh frozen plasma (FFP) and oral vitamin K(1) for five days and following drainage of the hemoperitoneum, the patient's bleeding tendency stopped, with slow decreases in PT and PTT. Compared to previous reports of superwarfarin intoxication of unknown exposure, this case is distinct in that the severe bleeding tendency needed surgical management and involved a suspected drug interaction with fluconazole. Therefore, superwarfarin intoxication should be suspected in subjects with markedly prolonged PT and PTT of unknown etiology, since a drug interaction could amplify the toxicity from a small exposure to superwarfarin.

Topics: 4-Hydroxycoumarins; Anticoagulants; Antifungal Agents; Drug Interactions; Fluconazole; Hemoperitoneum; Humans; Male; Middle Aged; Plasma; Prognosis; Prothrombin Time

Brodifacoum is a 4-hydroxycoumarin derivative that is commonly used as a rodenticide. Human exposures have produced severe coagulopathies resulting in hematuria, gastrointestinal bleeding, intracranial hemorrhage, and death. This is the first report of spontaneous hemoperitoneum secondary to brodifacoum ingestion. The patient was successfully managed with fresh frozen plasma, packed red blood cells, and vitamin K1. No surgical intervention was performed. The patient required ongoing daily vitamin K1 therapy for longer than 6 months.

Topics: 4-Hydroxycoumarins; Adult; Blood Component Transfusion; Drug Overdose; Erythrocyte Transfusion; Female; Hemoperitoneum; Humans; Plasma; Poisoning; Rodenticides; Vitamin K