What Is Linezolid? Uses, Dosage, and What You Need to Know in 2026

Linezolid is a synthetic antibiotic used to treat serious infections caused by drug-resistant gram-positive bacteria. You may have heard of it by its brand name, Zyvox. It's not a typical antibiotic — it was approved by the FDA in 2000 as the first member of the oxazolidinone class, filling a critical gap in the treatment of bacteria that had become resistant to most other antibiotics. Here's what patients and their families need to know.

What Is Linezolid Used For?

Linezolid is FDA-approved to treat several serious bacterial infections in both adults and children:

• Hospital-acquired (nosocomial) pneumonia caused by Staphylococcus aureus (including MRSA) or Streptococcus pneumoniae
• Community-acquired pneumonia caused by S. pneumoniae (including cases with concurrent bacteremia) or methicillin-susceptible S. aureus (MSSA)
• Complicated skin and skin structure infections caused by MRSA, MSSA, Streptococcus pyogenes, or Streptococcus agalactiae (including diabetic foot infections without osteomyelitis)
• Uncomplicated skin and skin structure infections caused by MSSA or S. pyogenes
• Vancomycin-resistant Enterococcus faecium (VRE) infections including infections complicated by bacteremia — linezolid is the only FDA-approved antibiotic specifically for VRE

It is also used off-label for bone and joint infections, meningitis in select situations, and as part of combination regimens for multi-drug resistant tuberculosis (MDR-TB).

What Bacteria Does Linezolid Target?

Linezolid is effective against gram-positive bacteria only — it has no activity against gram-negative organisms. Key bacteria it covers include:

• MRSA (methicillin-resistant Staphylococcus aureus)
• VRE (vancomycin-resistant Enterococcus faecium)
• Streptococcus pneumoniae (penicillin-susceptible and penicillin-resistant)
• Streptococcus pyogenes and Streptococcus agalactiae (group A and B streptococci)

What Dosage Forms Does Linezolid Come In?

Linezolid is available in three formulations:

• Oral tablet: 600 mg (white, capsule-shaped, film-coated tablet) — most common form for outpatient use
• Oral suspension: 100 mg/5 mL (orange-flavored liquid) — for patients who cannot swallow tablets; use within 21 days after mixing
• IV injection: 2 mg/mL solution in 100 mL or 300 mL bags — for hospitalized patients or those in home infusion programs

What Is the Typical Linezolid Dosage for Adults?

Dosage depends on the type and severity of infection:

• Pneumonia and complicated skin infections: 600 mg every 12 hours for 10–14 days (IV or oral)
• Uncomplicated skin infections: 400 mg orally every 12 hours for 10–14 days
• VRE infections: 600 mg every 12 hours for 14–28 days

Linezolid can be taken with or without food. The oral tablet and IV formulations are pharmacokinetically interchangeable, allowing patients to switch from IV to oral seamlessly.

Key Safety Information Every Patient Should Know

Before starting linezolid, make sure your doctor and pharmacist know about:

• All medications you're taking — especially antidepressants (SSRIs, SNRIs, MAOIs), opioid pain medications, triptans for migraines, and decongestants containing pseudoephedrine or phenylephrine
• Your complete diet — avoid tyramine-rich foods (aged cheese, cured meats, fermented foods, tap beer, red wine)
• Whether you have phenylketonuria (PKU) — the oral suspension contains aspartame

For a complete guide to linezolid's side effects and when to call your doctor, see our detailed article on linezolid side effects.