Table 1 Case vignettes and questions asked

Case 1:

A 60-year-old man (height 72 inches, weight 100 kg) with non-Hodgkin lymphoma requiring chemotherapy presents with fever (temperature in the emergency department 39.6°C), rigors, chills, and overall poor appetite. On examination of his catheter, notable erythema is around the catheter site. Paired blood cultures are obtained both centrally and peripherally. Twelve hours after admission, all four cultures grow gram-positive cocci in clusters. One month previously, he was treated for a methicillin-resistant Staphylococcus aureus (MRSA) skin/soft tissue abscess with trimethoprim/sulfamethoxazole and incision/drainage. After removing the catheter, the team starts him on Vancomycin 15–20 mg/kg intravenously every 8 hours. His most recent serum creatinine is 0.9 mg/dL.

What pharmacokinetic/pharmacodynamics principles would you implement to optimize the patient’s therapeutic regimen?

Case 2:

A 58-year-old woman with a history of recurrent urinary tract infections, presents with acute pyelonephritis. She has an allergy to penicillin (unknown), and sulfa drugs. She has no other comorbid conditions. She is placed on meropenem 1 g intravenously every 8 hours for initial treatment in the hospital. Her urine culture on hospital day 3 shows more than 100,000 Escherichia coli with the following susceptibilities (S=Sensitive, I=Intermediate, R=Resistant):

Ampicillin/sulbactam R, cefepime S, ceftriaxone S, ciprofloxacin S, ertapenem R, gentamicin I, meropenem R, piperacillin/tazobactam S, and trimethoprim/sulfamethoxazole S.

What management strategies would be best from two stewardship standpoints?

When would you consider stepping down to oral therapy appropriate? Justify your answer while providing a drug of choice.

Case 3:

This is a 186-bed hospital that has had a stewardship program for 2 years. Carbapenems use has decreased from prior efforts, yet rates of Clostridioides difficile infection are increasing. There is widespread use of other antipseudomonal beta-lactams empirically at this institution for unnecessary reasons, particularly if patients are doing well on them; once the antibiotic is started, it is hard to get it stopped.

What stewardship intervention is highly recommended for guiding appropriate empiric therapy selection for a patient with a specific infectious disease? Justify your answer.