Effect of rifampicin on anticoagulation of warfarin: A case report

BACKGROUND The drug interaction between warfarin and rifampicin is widely known, but there are still some difficulties in managing the combination of the two drugs. CASE SUMMARY A patient with brucellosis received strict monitoring from a Chinese pharmacist team during combination of warfarin and rifampicin. The dose of warfarin was increased to 350% in 3 mo before reaching the lower international normalized ratio treatment window. No obvious adverse reaction occurred during the drug-adjustment period. This is the first case report of long-term combined use of rifampicin and warfarin in patients with brucellosis and valve replacement in China based on the Chinese lower warfarin dose and international normalized ratio range. CONCLUSION Anticoagulation for valve replacement in Chinese patients differs from that in other races. Establishment of a pharmacist clinic provides vital assistance in warfarin dose adjustment.