Case 4 occurred in an 80-year-old female who was admitted due to increasing fatigue and copious diarrhea consistent with community onset CDI. Her risk factors for CDI included advanced age and recent antibiotic use (vancomycin, levofloxacin, and piperacillin–tazobactam). This patient’s initial severity of illness was mild (WBC 9,100/μL, serum creatinine 116% of the premorbid level) and she was treated with oral metronidazole 500 mg three times daily beginning on hospital day 1. After 3 days of metronidazole treatment, her abdominal pain had improved, but the diarrhea persisted and her WBC began trending upward (16,500/μL). On hospital day 4, the patient developed septic shock secondary to CDI. As her CDI had progressed to a severe complicated case, intravenous tigecycline and vancomycin 250 mg four times daily were added. Tigecycline was given as a 100-mg loading dose followed by 50 mg twice daily. The patient was treated successfully with 6 days of triple therapy with tigecycline, vancomycin, and metronidazole. Due to the high risk of CDI recurrence in this patient, a vancomycin taper was completed. The patient was discharged to home and had no CDI recurrence within 28 days of follow-up.
A 68-year-old Caucasian male with a history of multiple myeloma on lenalidomide/dexamethasone, diabetes, and end-stage renal disease on hemodialysis was admitted to the hospital for severe diarrhea and dehydration. On physical examination, he was found to be afebrile with benign abdominal exam. His white blood cell count (WBC) was normal. Fecal leukocytes were detected. Stool ova and parasites and bacterial stool cultures were negative. A computed tomography (CT) of the abdomen and pelvis showed diffuse thickening of the colon wall involving the entire colon and rectum consistent with infectious colitis. With the high suspicion of Clostridium difficile associated colitis, metronidazole 500 mg orally every 8 hours was empirically started. The cytomegalovirus serum polymerase chain reaction (PCR), enzyme immunoassay (EIA) for C. difficile toxin A/B and C. diffile PCR were all negative. Despite metronidazole treatment, his diarrhea persisted and on the 7th hospital day, he had a temperature of 101.8°F and rifaximin 550 mg orally twice daily was added. He responded rapidly to the combination treatment and the diarrhea and fever resolved by the 14th hospital day and he was discharged on metronidazole for 14 days. However, a week later the patient was readmitted to the hospital with diarrhea, nausea and abdominal pain. On physical examination, he was afebrile and appeared to be in mild distress with right-lower quadrant and suprapubic tenderness on palpation. His leukocyte count was 6,200 cells/μL and a repeat abdominal CT showed changes of pancolitis consistent with an infectious process. Metronidazole was continued and cefepime 1 gram intravenously every 24 hours was added. Stool culture showed only normal fecal flora and blood cultures were negative, however; the EIA C. difficile toxin stool assay was positive. His therapy was changed from metronidazole and cefepime to vancomycin 250 mg orally every 6 hours, as his symptoms restarted within 5 days of receiving rifaximin and while on metronidazole. Over the following nine days, the patient showed little response to therapy, averaging six loose bowel movements a day along with persistent abdominal tenderness and distention. He had a WBC count of 5,000 cells/μL with 32% bands, and a lactate level was elevated at 4 mmol/L. An abdominal X-ray showed no bowel distention. By the 10th hospital day, the patient developed leukocytosis with a WBC count of 17,200 cells/μL and was now considered to have failed vancomycin treatment. Tigecycline 100 mg intravenously once, followed by 50 mg every 12 hours and rifaximin 550 mg orally every 12 hours, was added to the vancomycin. Though the patient's leukocyte count peaked at 19,900 cells/μL (during 2nd day of modified therapy), he responded well with a gradual decrease in leukocytosis, diarrhea, and abdominal pain. He was discharged on the 16th hospital day with resolution of symptoms after 4 days of tigecycline, rifaximin, and vancomycin treatment. He was continued on this antibiotic regimen for an additional ten days. One month after finishing antibiotics, the patient was free of symptoms.