Version July 2025
ESBL: extended-spectrum beta-lactamases.
* Immunocompromising conditions include: poorly controlled diabetes mellitus, chronic high-dose corticosteroid use, use of other immunosuppressive agents, neutropenia, advanced HIV infection, B or T leukocyte deficiency.
¶ Health care exposures include: hospitalization, hemodialysis, residence in a long-term care facility, and intravenous antibiotic use or chemotherapy.
Δ Empiric therapy should be further tailored based on additional history, prior history of multidrug-resistant gram-negative pathogens, and likely source of infection. As an example, a carbapenem (imipenem or meropenem) is preferable for a patient with a history of infection with ESBL-producing organisms within the prior 6 months. Alternatively, for a patient with gram-negative bacteremia in the setting of cholangitis, a beta-lactam/beta-lactamase inhibitor or a carbapenem may be preferable to provide anaerobic coverage. For patients with sepsis or septic shock, broad-spectrum gram-positive coverage is often also used until cultures have been finalized. Drug dose lists are for adult patients with normal renal function. Refer to other UpToDate content for options for patients with severe beta-lactam allergies.
◊ For patients with gram-negative bacillary bacteremia and septic shock, we favor a prolonged infusion dosing strategy for most beta-lactams. Refer to other UpToDate content on prolonged infusions of beta-lactam antibiotics.
§ When there is a risk, we favor tobramycin over gentamicin or amikacin because tobramycin has greater intrinsic in vitro activity. Tobramycin dosing depends on the patient's weight and creatinine clearance. Dosing adjustments should be based on the results of serum drug concentration monitoring. Refer to other UpToDate content on aminoglycoside dosing.
