A 76-year-old woman, D.N., is hospitalized with a severe E. coliurinary tract infection (UTI). She has taken ciprofloxacin 500 mgevery 12 hours and is responding to it. Prior to admission, becauseshe is allergic to sulfamethoxazole, D.N. was taking amoxicillinwhich has been discontinued. D.N. takes digoxin 0.125 mg andpravastatin (Pravachol, Bristol-Myers Squibb) 20 mg daily. Over thepast 24 hours, she developed severe diarrhea and a 101?Ftemperature. Her stool specimen is positive for C. difficile. D.N.is receiving replacement fluids and electrolytes, but her physicianis considering how to resolve the C. difficile infection. What doyou recommend?