Diffuse Alveolar Hemorrhage Caused by Warfarin after Rifampicin Discontinuation

الملخص EN

An 83-year-old man under warfarin therapy presented for assessment of prolonged prothrombin time and cough.

High-resolution computed tomography findings of the chest showed diffuse alveolar hemorrhage.

His international normalized ratio (INR) was 11.89.

He had been treated with rifampicin for a persistent infection, but this had been discontinued about two months before admission.

Rifampicin suppresses the anticoagulant activity of warfarin, which can lead to a need for increased doses of warfarin to achieve and maintain a therapeutic INR.

More frequent INR monitoring is needed even after discontinuing rifampicin.