Linezolid
Zyvox
Oxazolidinone antibiotic (Gram-positive/MRSA/VRE)
Binds the 23S rRNA of the 50S subunit → blocks protein-synthesis initiation. Also a REVERSIBLE nonselective MAO inhibitor.
Indications
- •MRSA, VRE, resistant gram-positive infections
- •MRSA pneumonia (excellent lung penetration)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Typical | 600 mg IV/PO q12h (100% oral bioavailability) | — |
Pharmacokinetics
Excellent oral bioavailability. Hepatic/nonrenal metabolism.
Side effects
- !SEROTONIN SYNDROME (MAOI activity + SSRIs/SNRIs/meperidine/tramadol/methylene blue)
- !Myelosuppression/thrombocytopenia (>2 weeks)
- !Peripheral + optic neuropathy (prolonged)
- !Hypertension with sympathomimetics/tyramine
Contraindications
- ×Concurrent serotonergic drugs (relative — serotonin syndrome)
- ×Concurrent MAOIs
Clinical pearls
- ★ANESTHESIA KEY: linezolid is a REVERSIBLE MAOI → serotonin syndrome risk with meperidine, tramadol, methylene blue, SSRIs/SNRIs — screen the med list before choosing analgesics/dyes.
- ★Also causes hypertensive response to indirect sympathomimetics (ephedrine) + tyramine.
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
