Covert anticoagulant ingestion: study of 25 patients and review of world literature.

Twenty-five patients with covert ingestion of oral anticoagulant drugs were studied. Most of the patients were women who were either connected with the medical profession or were previously treated with antigoagulants. The most common findings were ecchymoses, hematuria, and a markedly prolonged prothrombin time. The anticoagulant drug was identified in the plasma of all 25 patients. Most patients responded promptly to administration of vitamin K1. The most common motives were malingering and suicide. The world literature was reviewed for covert ingestion of oral anticoagulant drugs and 48 other cases were found. The correct diagnosis is important to focus the physician's attention on the psychiatric rather than the somatic aspects of the disorder.