Linezolid

1. See Also
   1. Antibiotic Resistance
2. Indications
   1. Vancomycin Resistant Enterococcus
   2. Nosocomial Pneumonia
      1. Methicillin Resistant Staphylococcus Aureus
      2. Penicillin Sensitive Streptococcus Pneumoniae
   3. Complicated Skin Infections
      1. Methicillin Resistant Staphylococcus Aureus
      2. Streptococcus Pyogenes
      3. Streptococcus agalactiae
   4. Community Acquired Pneumonia (Not first line agent)
      1. Does not cover HaemophilusInfluenzae
      2. Methicillin Sensitive Staphylococcus aureus
      3. Penicillin Sensitive Streptococcus Pneumoniae
3. Mechanism
   1. Prototype for new Oxazolidinone Class
   2. Inhibits protein synthesis at unique site
   3. Spectrum
      1. Minimal activity against Gram Negative Bacteria
      2. Bacteriostatic activity
         1. Vancomycin Resistant Enterococcus faecium
         2. Methicillin Resistant Staphylococcus Aureus
      3. Bactericidal activity
         1. Streptococcus Pneumoniae
         2. Streptococcus Pyogenes
         3. Streptococcus agalactiae
4. Pharmacokinetics
   1. Half Life: 5 hours
   2. Near 100% bioavailability after oral intake
5. Dosing
   1. Linezolid 400 to 600 mg PO or IV q12 hours
   2. Administer intravenously over 30 to 120 minutes
6. Adverse Effects
   1. Rash
   2. Headache
   3. Diarrhea
   4. Nausea or Vomiting
   5. Insomnia
   6. Constipation
   7. Fever
   8. Myelosuppression (requires discontinuation)
      1. Thrombocytopenia (2.4%)
7. Drug Interactions
   1. No Cytochrome P450 activity or related drug interaction
   2. Reversible MAO inhibitor (Hypertensive response)
      1. Do not use with Tyramine Containing Foods
      2. Avoid with adrenergic drugs
         1. Avoid concurrent Pseudoephedrine use
         2. Use caution with concurrent Dopamine or Epinephrine
   3. Theoretical Serotonin Syndrome
      1. Not observed in clinical trials
      2. Use caution with SSRIAntidepressants
8. Monitoring: Weekly Complete Blood Count Indications
   1. Linezolid use longer than 2 weeks
   2. Preexisting Myelosuppression or risk factors
   3. Chronic infection on concurrent other antibiotics
9. Cost
   1. Costs $53 to $72 for each oral or intravenous dose
10. References
    1. (2000) Med Lett Drugs Ther 42:45-6
    2. Ament (2002) Am Fam Physician 65(4):663-70
    3. Moellering (2003) Ann Intern Med 138:135-42