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.