Pharmacology · Class
Oxazolidinones !
Synthetic antibiotics that block the start of bacterial protein synthesis; active against MRSA and VRE, also by mouth.
Updated 2026-11-01
What they are
A fully synthetic class (linezolid, tedizolid) for resistant gram-positive infections: MRSA, vancomycin-resistant enterococci and penicillin-resistant pneumococci. Linezolid is also part of some regimens for drug-resistant tuberculosis.
Mechanism of action
They bind the 23S rRNA of the 50S ribosomal subunit, at the peptidyl-transferase centre, and prevent formation of the functional 70S initiation complex. Because the site is unique, there is no cross-resistance with other protein-synthesis inhibitors. They are bacteriostatic against staphylococci and enterococci and bactericidal against most streptococci.
Target: 23S rRNA of the bacterial 50S ribosomal subunit
Drugs in this class
- LinezolidAn oral or IV oxazolidinone for MRSA, VRE and drug-resistant TB; watch platelets, nerves and serotonin-drug…Peptidyl-transferase centre of the 23S rRNA, 50S ribosomal subunit
- TedizolidA once-daily oxazolidinone, oral or IV, for gram-positive skin infections including MRSA; similar to linezolid.Peptidyl-transferase centre of the 23S rRNA, 50S ribosomal subunit
Test yourself
Think of the answer, then tap the question to see it.
At which step do oxazolidinones block protein synthesis?
At initiation: by binding the 23S rRNA of the 50S subunit they prevent assembly of the functional 70S initiation complex.
Why can linezolid cause serotonin syndrome?
It weakly inhibits monoamine oxidase, so serotonergic drugs such as SSRIs accumulate their effect.
Which toxicities appear mainly with long linezolid courses?
Myelosuppression (especially thrombocytopenia), peripheral and optic neuropathy, and lactic acidosis.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 60 (McGraw Hill, 2023); DailyMed - LINEZOLID tablet, film coated (DailyMed (U.S. National Library of Medicine), 2026); RCSB PDB - 4WFA: The crystal structure of the large ribosomal subunit of Staphylococcus aureus in complex with linezolid (RCSB Protein Data Bank, 2026).
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Representative model, for educational purposes only.