A 64 yo female is treated with warfarin for chronic atrial f

A 64 yo female is treated with warfarin for chronic atrial fibrillation. She develops acute pyelonephritis that requires ceftriaxone therapy.Soon after initiation of the treatment her laboratory testing reveals significantly increased prothrobin time and increased INR. Warfarin action is enhanced in this patient due to the effect on which of the following?

1. absorption
2. hepatic metabolism
3. plasma protein binding
4. competitive antagonism
5. renal excretion

2. hepatic metabolism...........cause warfarin is metabolized byhepatic p450.......also ceftraixone and cefoperazone are mainly excreted in bile........