Linezolid Oral Dosing and Frequency for Adults
The recommended oral dose of linezolid for adults is 600 mg twice daily (every 12 hours). 1, 2, 3
Standard Dosing Recommendations
- Linezolid 600 mg PO twice daily is the standard adult dose recommended by the Infectious Diseases Society of America for most infections 1, 2
- This dosing regimen applies to various infections including:
Pharmacokinetic Considerations
- Linezolid is rapidly and extensively absorbed after oral administration with approximately 100% bioavailability 3
- Maximum plasma concentrations are reached approximately 1-2 hours after oral dosing 3
- Linezolid may be administered without regard to the timing of meals, although high-fat food may delay the time to peak concentration by about 0.7 hours and decrease peak concentration by 17% (but total exposure remains similar) 3
- The elimination half-life is approximately 4-5 hours in adults with normal renal and hepatic function 3
Duration of Therapy
The duration of linezolid therapy varies depending on the type and severity of infection:
- Complicated skin and soft tissue infections: 7-14 days 2
- Pneumonia: 7-14 days 2
- Osteomyelitis: minimum of 8 weeks 2
- Meningitis: 2 weeks 2
- Brain abscess, subdural empyema, or spinal epidural abscess: 4-6 weeks 2
- Endocarditis (for vancomycin-resistant enterococci): >6 weeks 1
Special Considerations
- Monitoring is recommended for patients receiving linezolid for more than 14 days due to increased risk of thrombocytopenia 4
- Complete blood counts should be monitored weekly in patients receiving linezolid for extended periods 4
- Significant variability in drug exposure between patients has been observed, which may affect both efficacy and toxicity profiles 5, 6
- Thrombocytopenia risk increases with longer treatment durations, particularly beyond 10 days of therapy 6
- Linezolid is a weak, reversible monoamine oxidase inhibitor, so foods containing high concentrations of tyramine should be avoided 4
Dosing in Special Populations
- No dose adjustment is required when switching between oral and intravenous administration due to the 100% bioavailability of oral linezolid 3
- Patients with renal dysfunction may require closer monitoring as renal clearance accounts for approximately 30% of linezolid elimination 3, 5
- Therapeutic drug monitoring may be beneficial for patients requiring extended therapy or those with altered pharmacokinetics 5
The consistent recommendation across multiple guidelines and the FDA labeling supports the 600 mg twice daily oral dosing of linezolid for adult patients, with appropriate duration based on the specific infection being treated.