 The patient being on Coumadin I explained to him that unless there was a solid reason to put him on antibiotics, he would be advised not to do so because antibiotics can alter the gut floor causing the INR to increase while on Coumadin which may cause serious bleeding. 
The patient being on Coumadin I explained to him that unless there was a solid reason to put him on antibiotics , he would be advised not to do so because antibiotics can alter the gut floor causing the INR to increase while on Coumadin which may cause serious bleeding .