Case 7 occurred in a 73-year-old female who was initially admitted due to pneumonia and acute kidney injury. The patient was treated empirically with vancomycin, levofloxacin, and piperacillin-tazobactam. On hospital day 3, the patient developed copious diarrhea, nausea, leukocytosis (WBC 20,000/μL) and serum creatinine increased 151% of the premorbid level. Clostridium difficile toxin was detected and oral metronidazole 500 mg three times daily was initiated. Tigecycline was added on hospital day 5 based on recommendations by the consulting infectious diseases specialist. Tigecycline was initiated instead of vancomycin due to the additional coverage of the patient’s concomitant vancomycin-resistant enterococcal urinary tract infection. The patient was successfully treated with 4 days of combination therapy with tigecycline and metronidazole with resolution of all CDI symptoms. No side effects attributed to tigecycline use were noted, and she had no documented CDI recurrence 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.