Anyway, I have 2 cases of patients who are on long-term Coumadin therapy. The INR results make us wonder about the use of multiple CYP2C9 inhibitors with wafarin. Patient #1: 75 yo caucasian male with afib. Warfarin dosed at 24 mg/wk, chronically on Amiodarone ( 10 years d/t hx of ventricular arrhythmias). Started Bactrim DS x10 days on Jan 25th. He notified anticoag clinic on Jan 29th and his dose was reduced by 50% for 2 days and INR checked yesterday (day 6 of Bactrim). One would expect the INR to be somewhat elevated considering Bactrim-warfarin interaction, but INR. | Trường Hợp Lâm Sàng Dùng Warfarin Anyway I have 2 cases of patients who are on long-term Coumadin therapy. The INR results make us wonder about the use of multiple CYP2C9 inhibitors with wafarin. Patient 1 75 yo Caucasian male with afib. Warfarin dosed at 24 mg wk chronically on Amiodarone 10 years d t hx of ventricular arrhythmias . Started Bactrim DS x10 days on Jan 25th. He notified anticoag clinic on Jan 29th and his dose was reduced by 50 for 2 days and INR checked yesterday day 6 of Bactrim . One would expect the INR to be somewhat elevated considering Bactrim-warfarin interaction but INR was . Patient 2 77 yo african american male with Afib. Warfarin dosed at 40 mg wk on Amiodarone for past 4 months for afib. Started Bactrim DS x 7 days on Jan 25th. He notified anticoag clinic on Jan 25 and his dose was reduced to mg daily little more than 50 dose reduction . INR check yesterday day 6 of Bactrim . INR was below therapeutic since slightly greater than 50 dose reduction for ease in patient instructions. Patient 1 is still presenting a challenge- after the 1 31 INR the dose of warfarin adjusted to only a 19 reduction from his maintenance dose rather than the initial 50 reduction but his INR continued to drop to . He is now finished with bactrim so have now resumed his usual 24 mg wk with an INR scheduled later this week. Patient 2 was pretty straightforward as he only had 3 doses of bactrim remaining. His usual 40 mg wk dosage was resumed and his INR on 2 14 was After all the prevailing theory is more related to interpersonal differences in metabolism producing the varying response to bactrim. Having said that no one could eliminate the chance that multiple 2C9 inhibitors made a difference. Let s me know your thought on this subject Christina Christina Cao Desert Valley Medical Center 16850 Bear Valley Road Victorville CA 92395 GIẢI THÍCH 2 CA DÙNG WARFARIN CHO DƯỢC SĨ TẠI VIỆT-NAM Ds Lê Văn Nhân Lời nói đầu Tại Việt-nam các bác
