A Mysterious Cause of Coagulopathy With Bleeding Diathesis

Vitamin K is essential to produce functional vitamin K-dependent coagulation factors (prothrombin, factors VII, IX, and X). Vitamin K antagonists inhibit the normal activation of these factors, leading to bleeding manifestations of variable severity. Long-acting vitamin K antagonists or superwarfarins were developed as rodenticides and have a significantly longer half-life and greater potency when compared to warfarin. Intoxication with superwarfarins presents a typical clinical picture and evolution, but its diagnosis can be challenging without a clear ingestion history. We describe a case of a healthy 67-year-old man who presented with bleeding diathesis and severe anemia due to isolated coagulopathy. Laboratory evaluation showed prolonged coagulation times and very low levels of vitamin K-dependent coagulation factors. All other potential causes were ruled out, and superwarfarin intoxication was assumed, although we were unable to confirm unequivocal exposure. He was treated with high-dose vitamin K supplementation for two months until coagulation times normalized. He remained asymptomatic with no laboratory changes four months after the suspension of vitamin K.The management of a patient presenting with bleeding diathesis and coagulopathy can be challenging. A stepwise approach is helpful to reach the correct diagnosis and intoxication with long-acting vitamin K antagonists should be considered, even without an ingestion history. Therapy with vitamin K in high doses must be started as soon as possible and can be lifesaving.