Piperacillin-Tazobactam
Zosyn
Antipseudomonal penicillin + β-lactamase inhibitor
Piperacillin (broad, antipseudomonal) + tazobactam (β-lactamase inhibitor) → very broad gram-positive/negative/anaerobic + Pseudomonas.
Indications
- •Broad empiric coverage (sepsis, intra-abdominal, nosocomial pneumonia, febrile neutropenia)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Serious infection | 3.375–4.5 g IV q6–8h (extended infusion common) | — |
Pharmacokinetics
Half-life ~1 h. Renally cleared.
Side effects
- !Penicillin allergy
- !AKI (↑ when combined with vancomycin — nephrotoxic synergy)
- !C. difficile
- !Hypokalemia (high sodium load)
Contraindications
- ×Penicillin allergy
Clinical pearls
- ★Vanc + Zosyn together raises AKI risk — a well-known nephrotoxic combination; monitor renal function.
- ★Very broad empiric workhorse including Pseudomonas.
Other drugs in Antibiotics
- Cefazolin
β-lactam — inhibits bacterial cell wall PBPs.
- Vancomycin
Inhibits cell wall synthesis (binds D-Ala-D-Ala). Active against MRSA + gram-positives.
- Clindamycin
Binds 50S ribosomal subunit, blocks peptide-bond formation. Bacteriostatic against most organisms; bactericidal against susceptible streptococci. Excellent activity against anaerobes and gram-positive cocci including community-acquired MRSA.
- Gentamicin
Binds 30S ribosomal subunit, causes misreading of mRNA → defective bacterial protein synthesis. Bactericidal, concentration-dependent killing. Synergy with cell-wall agents (β-lactams, vancomycin) for gram-positive endocarditis.
- Cefuroxime
β-lactam — inhibits cell-wall synthesis (PBP binding). 2nd-gen: gram-positive + expanded gram-negative.
- Cefepime
β-lactam cell-wall inhibitor. Broad gram-negative (incl. Pseudomonas) + gram-positive coverage.
- Cefotetan
β-lactam; adds anaerobic (B. fragilis) coverage → colorectal/gynecologic prophylaxis.
- Cefotaxime
β-lactam cell-wall inhibitor. Broad gram-negative + CNS penetration.
Browse all classes: /reference/drugs
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
