Effects of Teicoplanin on the PT-INR Controlled by Warfarin in Infection Patients

Abstract

Warfarin (WF) shows a number of interactions with other drugs, which alter its anticoagulant eŠects. The albumin binding interaction is one such pharmacokinetic mechanism of drug interaction with WF, which induces a rise in the free WF concentration and thus increases the risk of WF toxicity. Teicoplanin (TEIC) is an anti-methicillin-resistant Staphylococcus aureus drug, which also binds strongly to albumin in the plasma. Therefore, co-administration of TEIC may displace WF from the albumin binding site, and possibly result in a toxicity. The present study was performed to investigate the drug-drug interaction between WF and TEIC in comparison with controls treated with vancomycin (VCM), which has the same spectrum of activity as TEIC but a lower albumin binding ratio.The records of 49 patients treated with WF and TEIC or VCM at Fukuoka University Hospital between 2010 and 2015 were retrospectively reviewed. These 49 patients consisted of 18 treated with TEIC in combination with WF, while 31 received VCM in combination with WF. Prothrombin time-international normalized ratio (PT-INR) showed a signiˆcant increase of 80.9 (52.0 155.3) ％ after co-administration of TEIC with WF. In contrast, the rate of PT-INR elevation associated with VCM plus WF was 30.6 (4.5 44.1) ％. These observations suggested that TEIC can cause a rise in free WF concentration by albumin binding interaction. Therefore, careful monitoring of PT-INR elevation is necessary in patients receiving WF plus TEIC.

International normalized ratio for the guidance of warfarin treatment in elderly patients after cardiac valve replacement

“…Over the past half century, the number of patients receiving cardiac valve replacement was estimated to be 100,000 per annum worldwide. In China, the cardiac valve replacements account for 30% of those performed worldwide (11). Rheumatic heart disease is one of the most common types of heart disease, the major causative factor of which is the valve damage caused by inflammation, which leads to problems in the process of transfusion of blood in the patient's heart, including ventricular hypertrophy and dyspnea, while the severe form of the disease may pose a threat to the life of affected patients (12,13).…”