Abstract: Tuberculosis (TB) is a major infectious disease that seriously jeopardizes human health, and TB patients are at high risk of venous thromboembolism (VTE). Anticoagulant drugs are an important measure for treating VTE. However, Rifampicin, as an important drug in anti-tuberculosis treatment, has drug-drug interactions with a larger number of anticoagulant drugs, so it is important to explore the option of anticoagulant regimen when Rifampicin is used in TB patients. In this paper, a 69-year-old female TB patient was reported, who was admitted to the hospital with ultrasound suggesting thrombosis of the posterior tibial veins and intermuscular veins of both lower limbs, and was treated with Warfarin for anticoagulation, which resulted in an extremely unstable international normalized ratio. Then, Warfarin was discontinued and replaced with Edoxaban, and a review after 3 months of treatment suggested that VTE of the lower limbs disappeared, and the lung lesions were obviously absorbed and improved. In this case, the treatment results and DDI data showed that the use of Edoxaban is safer and more effective for patients who need to take a combination of Rifampicin and anticoagulant drugs, which ensures the completeness of the anti-tuberculosis regimen and the effectiveness of anticoagulation therapy, and also enables a better early therapeutic effect in TB patients.

Key words: Rifampin, Pulmonary tuberculosis, Deep vein thrombosis, Warfarin, Edoxaban