Linezolid
An oxazolidinone for serious Gram-positive infections such as MRSA and VRE, and part of 6-month regimens for drug-resistant TB.
Drug card
- Class
- Oxazolidinone
- How it works
- Blocking formation of the 70S initiation complex on the 50S subunit
- Used for
- Vancomycin-resistant Enterococcus faecium infections
- MRSA infections
- Hospital-acquired and community-acquired pneumonia
- Complicated skin infections, including diabetic foot
- Known for
- Myelosuppression: low platelets, anemia, low white cells
- Serotonin syndrome with serotonergic drugs
- Optic and peripheral neuropathy on long courses
- Its name
- -zolid means an oxazolidinone antibacterial
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does linezolid work?
Linezolid binds the 23S rRNA of the 50S subunit and prevents a working 70S initiation complex from forming. It is bacteriostatic against staphylococci and enterococci and bactericidal against most streptococci. It is about 100% absorbed by mouth, and as a reversible, non-selective MAO inhibitor it interacts with serotonergic and adrenergic drugs.
Uses
What is linezolid used for?
- Vancomycin-resistant Enterococcus faecium infections
- MRSA infections
- Hospital-acquired and community-acquired pneumonia
- Complicated skin infections, including diabetic foot
- Drug-resistant tuberculosis (BPaLM and BPaL regimens)
Side effects
Side effects of linezolid
- Myelosuppression: low platelets, anemia, low white cellsKnown forSerious
- Serotonin syndrome with serotonergic drugsKnown forSerious
- Optic and peripheral neuropathy on long coursesKnown forSerious
- Low platelets, mostly after 2 weeks of useSerious
- Lactic acidosisSerious
- Low blood sugar in people taking diabetes drugsSerious
- Low sodium (hyponatremia, SIADH)Serious
- SeizuresSerious
- Muscle breakdown (rhabdomyolysis)Serious
- Tooth and tongue discoloration, removable
- Altered or metallic taste
- Vaginal thrush (candidiasis)
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Contraindicated with MAO inhibitors or within 2 weeks of one; serotonergic drugs such as SSRIs, triptans and opioids risk serotonin syndrome.
- Check blood counts weekly; low platelets are commoner after 2 weeks and in severe kidney or moderate to severe liver impairment.
- People with diabetes on insulin or oral hypoglycemics can become hypoglycemic; older people and diuretic users need sodium checks.
- Not for Gram-negative or catheter-related bloodstream infections, where linezolid was linked to excess deaths in a trial.
Good to know: It also inhibits human mitochondrial protein synthesis, which explains its lactic acidosis, anemia and neuropathy, mostly beyond 28 days. Near-complete oral absorption lets it switch from IV to tablets at the same dose.
Remember it
A way to remember it
MAO
- M
- Myelosuppression, especially low platelets
- A
- Antidepressant clash: serotonin syndrome with serotonergic drugs
- O
- Optic neuropathy and vision loss on long courses
Fitting, because linezolid is itself a reversible MAO inhibitor.
Written for biofideX
Its name
-zolid means oxazolidinone antibacterial
Linezolid and tedizolid share it; linezolid blocks an early step of bacterial protein synthesis.
- Every drug name stem
Its class
Oxazolidinones
Oxazolidinones such as linezolid and tedizolid bind the 23S rRNA of the 50S subunit and stop a working 70S initiation complex from forming, so translation never starts, a mechanism unique among antibiotics. They treat Gram-positive infections, including MRSA, but not Gram-negative ones. Linezolid also reversibly inhibits MAO and human mitochondrial protein synthesis, the root of several of its toxicities.
Easily mixed up with glycopeptides and macrolides.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Linezolid for oral suspension: label (DailyMed)
- Linezolid injection: label (DailyMed)
- Linezolid 600 mg film-coated tablets: SmPC (emc)
- Linezolid (NCI Thesaurus)
- Pretomanid tablets: label (DailyMed)
- Treatment for Drug-Resistant Tuberculosis Disease (CDC)
- Linezolid (WHO eEML)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antibiotics: protein synthesis
Linezolid is one of 10 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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