Case 2 occurred in a 46-year-old male who was admitted to the ICU with severe diarrhea and septic shock requiring 13 L fluid resuscitation and vasopressors. The patient presented with severe leukocytosis (WBC 35,400/μL) and renal impairment (serum creatinine increased 166% of the premorbid level). This patient had a number of risk factors for CDI, including admission from a long-term care facility and multiple prior antibiotic use (see Table for full listing). He was treated initially with oral metronidazole 500 mg three times daily. Oral metronidazole was switched to intravenous and oral vancomycin 125 mg four times daily was added on hospital day 2 upon detection of toxigenic C. difficile. At this point, the patient was intubated due to decreasing respiratory function and pulmonary edema. He also had other symptoms of severe complicated CDI, included nausea and vomiting, abdominal pain, colonic wall thickening, and ascites. Oral vancomycin was changed to rectal vancomycin 500 mg four times daily on hospital day 3 due to the development of paralytic ileus. This regimen continued through hospital day 7, with fever, ileus, and abdominal pain resolving. On hospital day 8, the patient again developed diarrhea with abdominal pain and persisting leukocytosis (WBC 24,300/μL). Due to these non-resolving symptoms and the severity of the patient’s condition, intravenous tigecycline was added on hospital day 8 as a 100-mg loading dose followed by 50 mg twice daily. Clinical cure was achieved after 8 days of treatment with tigecycline, rectal vancomycin, and intravenous metronidazole. Due to the high risk of recurrence, the patient completed a vancomycin taper upon discharge to a long-term care facility. There was no documented recurrence of CDI on record.
Case 5 occurred in a 68-year-old male who was admitted to the hospital for febrile neutropenia secondary to pre-B cell acute lymphoblastic leukemia. This patient had multiple risk factors for CDI, including advanced age, hematologic malignancy, multiple prior antibiotic use (trimethoprim–sulfamethoxazole, levofloxacin, linezolid, and cefepime), prior chemotherapy use, and hospitalization. On hospital day 6, the patient developed acute respiratory distress and severe sepsis (4/4 SIRS criteria). On hospital day 7, the patient developed diarrhea and C. difficile toxin was detected. This case was classified as severe complicated CDI and treated initially with two days of intravenous metronidazole 500 mg three times daily and oral vancomycin 125 mg four times daily. On hospital day 9, tigecycline was added due to persisting diarrhea (>800 mL liquid stool) and fever (38.2 °C). The patient’s fever resolved on hospital day 11, diarrhea resolved on hospital day 14, and clinical cure was achieved. Triple therapy with tigecycline, vancomycin, and metronidazole was continued for a total of 21 days due to concerns for recurrence in the context of the patient’s pancytopenia. At this time, the patient was switched to palliative care due to underlying cancer with a poor overall prognosis. He tolerated treatment with tigecycline well and no side effects were reported. The patient was discharged home to hospice with no further CDI treatment. Sustained response was unevaluable due to death within 28 days of tigecycline completion.