Ertapenem
Invanz
Carbapenem β-lactam (once-daily, NO pseudomonal coverage)
Broad-spectrum carbapenem; long half-life → once-daily. Does NOT cover Pseudomonas or Acinetobacter (unlike imipenem/meropenem).
Indications
- •Community-acquired intra-abdominal/pelvic infections, complicated UTI, diabetic foot
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Typical | 1 g IV daily | — |
Pharmacokinetics
Long half-life ~4 h → once-daily. Renally cleared.
Side effects
- !Seizure (less than imipenem)
- !C. difficile
- !β-lactam allergy
Contraindications
- ×Severe β-lactam allergy
Clinical pearls
- ★Once-daily carbapenem but NO Pseudomonas coverage — the key distinction from imipenem/meropenem.
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.
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
