Weitzel J N, Sadowski J A, Furie B C, Moroose R, Kim H, Mount M E, Murphy M J, Furie B
Division of Hematology-Oncology, New England Medical Center, Boston, MA.
Blood. 1990 Dec 15;76(12):2555-9.
The vitamin K metabolism of three patients with factitious purpura due to brodifacoum ingestion was studied. These patients, who presented with bleeding disorders due to deficiency of the vitamin K-dependent blood clotting proteins, were refractory to vitamin K1 at standard doses and required fresh frozen plasma to control bleeding until large doses of vitamin K1 were used. Metabolic studies demonstrated a blockade in vitamin K utilization, consistent with the presence of a vitamin K antagonist, but the patients denied use of anticoagulants. Warfarin assays were negative. We show that the factitious purpura in each patient was due to the surreptitious ingestion of brodifacoum, a potent second generation long-acting vitamin K antagonist used as a rodenticide. The coagulopathies responded to long-term therapy with large doses of vitamin K1. The serum elimination half-time for brodifacoum ranged from 16 to 36 days in these patients. The anticoagulant effect is of long duration, requiring chronic vitamin K treatment. With increasing availability of new rodenticides, factitious purpura due to surreptitious ingestion of these potent vitamin K antagonists is emerging as a new problem, previously associated with warfarin, with important implications for diagnosis and treatment.
对3例因摄入溴敌隆导致人为性紫癜患者的维生素K代谢进行了研究。这些患者因维生素K依赖的血液凝固蛋白缺乏而出现出血性疾病，对标准剂量的维生素K1无效，在使用大剂量维生素K1之前需要输注新鲜冰冻血浆来控制出血。代谢研究表明维生素K利用受阻，这与维生素K拮抗剂的存在一致，但患者否认使用过抗凝剂。华法林检测呈阴性。我们发现，每名患者的人为性紫癜是由于偷偷摄入了溴敌隆，一种用作灭鼠剂的强效第二代长效维生素K拮抗剂。凝血病对大剂量维生素K1的长期治疗有反应。这些患者中溴敌隆的血清消除半衰期为16至36天。抗凝作用持续时间长，需要长期维生素K治疗。随着新型灭鼠剂的可得性增加，因偷偷摄入这些强效维生素K拮抗剂导致的人为性紫癜正成为一个新问题，以前与华法林有关，对诊断和治疗具有重要意义。
