What is the use of Linezolid (an oxazolidinone antibiotic)?

From the Guidelines

Linezolid is an oxazolidinone antibiotic primarily used to treat serious infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), with a recommended dosage of 600 mg twice daily for 10-14 days, depending on the infection type, as supported by the most recent guidelines 1. The use of linezolid is recommended for the management of skin and soft-tissue infections, including those caused by MRSA, due to its effectiveness and high bioavailability, allowing for easy transition between oral and intravenous formulations 1. Some key points to consider when using linezolid include:

• Its mechanism of action, which involves inhibiting bacterial protein synthesis through binding to the 23S ribosomal RNA of the 50S subunit, preventing formation of the functional 70S initiation complex 1.
• Common side effects, such as headache, nausea, diarrhea, and potential myelosuppression with prolonged use, particularly thrombocytopenia, which requires monitoring with weekly complete blood counts if treatment exceeds 14 days 1.
• Significant drug interactions, particularly with serotonergic medications, as it functions as a reversible monoamine oxidase inhibitor, potentially causing serotonin syndrome, and the need to limit tyramine-rich foods during treatment to avoid hypertensive crises 1.
• The importance of individualizing treatment duration based on the patient's clinical response, with a recommended duration of 7-14 days, and the possibility of switching from intravenous to oral therapy when criteria of clinical stability have been reached 1.

From the FDA Drug Label

Linezolid is a synthetic antibacterial agent of a new class of antibiotics, the oxazolidinones, which has clinical utility in the treatment of infections caused by aerobic Gram-positive bacteria. The in vitro spectrum of activity of linezolid also includes certain Gram-negative bacteria and anaerobic bacteria Linezolid has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections, as described in the INDICATIONS AND USAGE section Aerobic and facultative Gram-positive microorganisms Enterococcus faecium (vancomycin-resistant strains only) Staphylococcus aureus (including methicillin-resistant strains) Streptococcus agalactiae Streptococcus pneumoniae (including multi-drug resistant isolates [MDRSP]1) Streptococcus pyogenes

The use of Linezolid is for the treatment of infections caused by aerobic Gram-positive bacteria, including vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, and multi-drug resistant Streptococcus pneumoniae. It is also active against other Gram-positive microorganisms, such as Streptococcus agalactiae and Streptococcus pyogenes. 2

From the Research

Use of Linezolid

• Linezolid is an oxazolidinone antibiotic used to treat serious Gram-positive infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA) 3, 4, 5, 6, 7.
• It is effective against complicated skin and soft tissue infections, nosocomial pneumonia, community-acquired pneumonia, and uncomplicated skin and skin structure infections 3, 5, 7.
• Linezolid has been shown to be as efficacious as vancomycin for suspected or proven methicillin-resistant staphylococcal infections 3.
• The oral bioavailability of linezolid is approximately 100%, allowing for sequential intravenous-to-oral administration without changing the drug or dosage regimen 4, 7.
• Linezolid may be particularly useful as an alternative to vancomycin in patients who have impaired renal function, poor or no intravenous access, require outpatient therapy, or who have been unable to tolerate glycopeptides 4.

Clinical Applications

• Linezolid is used to treat infections caused by drug-resistant Staphylococcus aureus, including MRSA 6.
• It is probably the drug of choice for the treatment of complicated MRSA skin and soft tissue infections 6.
• Linezolid has been shown to be non-inferior to vancomycin in the treatment of complicated skin and soft tissue infections 3, 4.
• It may also be used to treat nosocomial pneumonia, community-acquired pneumonia, and uncomplicated skin and skin structure infections 5, 7.

Pharmacological Properties

• Linezolid acts as an inhibitor of bacterial protein synthesis by blocking the formation of the 70S ribosomal initiation complex 7.
• Its activity is bacteriostatic against some species and bactericidal against others 7.
• The antibacterial spectrum of linezolid includes Gram-positive pathogens and some Gram-negative anaerobic species but not Gram-negative aerobes 7.