Daptomycin
Cubicin
Cyclic lipopeptide antibiotic (Gram-positive/MRSA/VRE)
Inserts into the gram-positive cell membrane (calcium-dependent) → depolarization → cell death. Bactericidal.
Indications
- •MRSA bacteremia/endocarditis
- •Complicated skin/soft-tissue infection
- •VRE
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Typical | 4–6 mg/kg IV daily (8–10 mg/kg for bacteremia/endocarditis; renally adjusted) | — |
Pharmacokinetics
Half-life ~8 h → once-daily. Renally cleared.
Side effects
- !MYOPATHY / rhabdomyolysis (monitor CK weekly; hold statins)
- !Eosinophilic pneumonia
- !INACTIVATED BY PULMONARY SURFACTANT
Contraindications
- ×Pneumonia (does NOT work — surfactant inactivates it)
Clinical pearls
- ★NEVER for pneumonia — pulmonary surfactant inactivates it (the classic board fact).
- ★Monitor CK for myopathy; consider holding statins during therapy.
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
