the workhorse
An antipseudomonal penicillin combined with a beta-lactamase inhibitor. First-line for “hospital-acquired” sepsis (HAP, intra-abdominal, febrile neutropenia).
- Mechanism: Cell wall synthesis inhibitor + Beta-lactamase decoy.
- Dosing:
- Standard: 3.375 g IV q6h.
- Severe/Pseudomonas: 4.5 g IV q6h (or extended infusion over 4h).
- Renal Adjustment: Required.
spectrum
- Gram Positive: Strep, Enterococcus faecalis (NOT VRE), MSSA (NOT MRSA).
- Gram Negative: Pseudomonas, E. coli, Klebsiella, Enterobacter. (Variable ESBL activity - Carbapenems preferred for serious ESBL).
- Anaerobes: Excellent coverage (B. fragilis).
clinical pearls
- “Nephrotoxicity”: Synergistic AKI when combined with Vancomycin.
- Sodium Load: High sodium content (avoid in severe heart failure if possible).
- False Positives: Can cause false-positive Galactomannan (Aspergillus) test (older formulations/generics).