The dangers of mixing medicines

A patient's toe infection leads to something life-threatening

Betsy, an 88-year-old woman from a low-level care nursing home was referred to the ED with a supra-therapeutic INR, after a routine pathology sample detected a ‘high’ reading. 

She had been taking warfarin for atrial fibrillation. Her INR was typically stable and therapeutic. 

Betsy had completed four courses of amoxycillin for a toe infection three weeks prior to admission. Her INR was closely monitored and remained stable within her target INR range of 2 to 3. 

Two weeks prior to admission, her GP