What is the recommended dosage and treatment duration for oral linezolid in treating bacterial infections?

Oral Linezolid Dosage and Treatment Duration for Bacterial Infections

The recommended dosage for oral linezolid is 600 mg every 12 hours for adults and adolescents (≥12 years), with treatment duration ranging from 10-14 days for skin/soft tissue infections to 14-28 days for more serious infections such as vancomycin-resistant Enterococcus faecium. 1

Adult Dosing Recommendations

Standard Adult Dosing

• Adults and adolescents ≥12 years: 600 mg orally every 12 hours 1, 2
• Uncomplicated skin infections in adults: 400 mg orally every 12 hours 1

Pediatric Dosing

• Children <5 years: 10 mg/kg orally every 8 hours 1
• Children 5-11 years: 10 mg/kg orally every 12 hours 1
• Adolescents ≥12 years: 600 mg orally every 12 hours 1

Treatment Duration by Infection Type

Skin and Soft Tissue Infections

• Uncomplicated: 10-14 days 1
• Complicated: 10-14 days 1

Respiratory Infections

• Community-acquired pneumonia: 10-14 days 1
• Nosocomial pneumonia: 14-28 days 1

Serious Infections

• Vancomycin-resistant Enterococcus faecium infections: 14-28 days 1
• MRSA infections: 10-14 days for skin infections; longer for more serious infections 2
• Osteomyelitis: >6 weeks 2
• Septic arthritis: 3-4 weeks 2, 3
• CNS infections: 14 days for meningitis; 4-6 weeks for brain abscess 2

Special Considerations

Efficacy

• Linezolid has demonstrated high clinical cure rates (88.6%) in complicated skin and soft tissue infections 4
• In a compassionate-use program for multidrug-resistant gram-positive infections, linezolid showed clinical cure rates of 73.3% in the intent-to-treat population and 91.5% at test of cure assessment 5

Pharmacokinetics

• Linezolid is fully bioavailable following oral administration 6
• Maximum plasma concentrations are usually achieved between 1-2 hours after oral administration 6
• Food slightly decreases the rate but not the extent of absorption 6
• Elimination half-life is 5-7 hours 6

Monitoring and Safety

• Monitor for thrombocytopenia, which occurs in approximately 7.4% of patients 5
• Gastrointestinal disturbances (9.8%), decreased hemoglobin/hematocrit (4.1%), and cutaneous reactions (4.0%) are other common adverse events 5
• Therapeutic drug monitoring may be beneficial for optimizing dosing, especially in patients with renal insufficiency, children, or those on medications that interact with linezolid 7

Switching from IV to Oral Therapy

• No dose adjustment is necessary when switching from intravenous to oral administration 1
• Patients can be switched from IV to oral linezolid when clinically indicated 1

Practical Application

1. Assess infection type and severity to determine appropriate duration
2. Consider patient factors (age, renal function) for potential dose adjustments
3. Monitor for adverse effects, particularly with longer treatment courses
4. Consider therapeutic drug monitoring for special populations or extended therapy

Linezolid's excellent oral bioavailability makes it particularly valuable for outpatient treatment of serious gram-positive infections, including those caused by resistant organisms like MRSA and VRE 8.