Linezolid: Recommended Use and Dosage for Bacterial Infections
Linezolid should be administered at 600 mg orally or intravenously twice daily for adults when treating serious bacterial infections, with treatment duration ranging from 10-28 days depending on the specific infection type. 1
Indications and Approved Uses
Linezolid is an oxazolidinone-class antibacterial indicated for the treatment of:
- Nosocomial pneumonia
- Community-acquired pneumonia, including concurrent bacteremia
- Complicated skin and skin structure infections
- Uncomplicated skin and skin structure infections
- Vancomycin-resistant Enterococcus faecium infections, including concurrent bacteremia 1
Dosage Recommendations
Adult Dosing:
- Standard dose: 600 mg orally or intravenously every 12 hours 1
- Uncomplicated skin infections: 400 mg orally every 12 hours 1
- Duration of therapy:
- Pneumonia: 10-14 days
- Complicated skin infections: 10-14 days
- Vancomycin-resistant enterococcal infections: 14-28 days
- Uncomplicated skin infections: 10-14 days 1
Pediatric Dosing:
- Children <12 years: 10 mg/kg orally or intravenously every 8 hours 1
- Adolescents ≥12 years: Same as adult dosing (600 mg every 12 hours) 1
- Uncomplicated skin infections in children:
- <5 years: 10 mg/kg orally every 8 hours
- 5-11 years: 10 mg/kg orally every 12 hours 1
Special Considerations
Renal Function
- No dosage adjustment is required for patients with renal impairment 2
- This makes linezolid preferable over vancomycin in patients with fluctuating renal function 2
Monitoring Requirements
- Complete blood counts: Monitor weekly, particularly in patients receiving treatment for longer than two weeks 1
- Visual function: Monitor for symptoms of visual impairment (changes in visual acuity, color vision, blurred vision) 1
Specific Infection Scenarios
MRSA Infections
- Linezolid is recommended as an alternative to vancomycin for MRSA infections 3, 2
- For MRSA pneumonia, linezolid shows higher clinical cure rates compared to vancomycin 2
- For complicated skin and skin structure infections due to MRSA, linezolid demonstrates comparable efficacy to vancomycin 4, 5
Enterococcal Infections
- For vancomycin-resistant enterococci (VRE), linezolid 600 mg IV or PO every 12 hours is strongly recommended 3
- Clinical and microbiological cure rates for VRE infections treated with linezolid are 81.4% and 86.4%, respectively 3, 6
Adverse Effects and Precautions
Major Adverse Effects
- Myelosuppression: Including anemia, leukopenia, pancytopenia, and thrombocytopenia 1
- Peripheral and optic neuropathy: Particularly with treatment longer than 28 days 1
- Gastrointestinal effects: Diarrhea, nausea, and vomiting 2, 6
Important Precautions
- Treatment duration: The safety and efficacy of linezolid given for longer than 28 days have not been evaluated in controlled clinical trials 1
- Serotonin syndrome: Use with caution in patients taking serotonergic medications 1
- Gram-negative coverage: Linezolid is not indicated for Gram-negative infections; specific Gram-negative therapy should be initiated if a concomitant Gram-negative pathogen is documented or suspected 1
Clinical Pearls
- Linezolid has 100% oral bioavailability, allowing for easy transition from IV to oral therapy without dose adjustment 1, 5
- For serious MRSA infections with poor response to vancomycin after 48-72 hours, consider switching to linezolid 2
- Avoid linezolid or use with caution when treatment duration is expected to exceed 14 days due to increased risk of myelosuppression 2, 1
- Monitor complete blood counts weekly in patients receiving linezolid for extended periods 1
Linezolid represents an important therapeutic option for serious Gram-positive infections, particularly those caused by resistant organisms such as MRSA and VRE, with the advantage of both oral and intravenous formulations having equivalent bioavailability.