Linezolid Dosing Recommendations
The standard dose of linezolid is 600 mg IV or PO every 12 hours for adults treating MRSA and VRE infections, with pediatric patients under 12 years receiving 10 mg/kg every 8 hours (maximum 600 mg per dose). 1
Standard Adult Dosing
Administer 600 mg IV or PO every 12 hours for complicated skin and soft tissue infections, nosocomial pneumonia, community-acquired pneumonia, vancomycin-resistant Enterococcus faecium infections, MRSA bacteremia, osteomyelitis, septic arthritis, and CNS infections 1
This fixed dosing regimen has demonstrated high clinical cure rates (91.5%) and microbiological success (85.8%) in real-world compassionate use programs involving multidrug-resistant gram-positive infections 2
Never reduce dosing frequency to every 24 hours, as this fails to maintain adequate drug exposure for bactericidal activity 1
Pediatric Dosing
Children under 12 years: 10 mg/kg IV or PO every 8 hours, not to exceed 600 mg per dose 1
Children 12 years and older: 600 mg IV or PO every 12 hours (adult dosing) 1
Special Populations and Dose Adjustments
While standard dosing applies to most patients, emerging pharmacokinetic data suggests potential modifications in specific scenarios:
Patients with augmented renal clearance (CrCL ≥ 60 mL/min/1.73 m²) may benefit from dose escalation to 450 mg every 8 hours to achieve optimal pharmacodynamic targets 3
Patients with reduced renal function (CrCL < 130 mL/min/1.73 m²) and coagulase-negative staphylococcal infections may require dose reduction to 450 mg every 12 hours 3
Do not escalate to 600 mg every 8 hours due to unacceptably high risk of thrombocytopenia 3
For enterococcal infections with higher MICs, some evidence suggests 600 mg every 8 hours may be required, though this must be balanced against toxicity risk 4
Treatment Duration by Indication
Uncomplicated skin and skin structure infections: 10-14 days 1
Septic arthritis: 3-4 weeks 1
CNS infections (meningitis, brain abscess): 2-6 weeks depending on specific infection 1
Osteomyelitis: Minimum 6-8 weeks, with consideration for additional 1-3 months of oral therapy 1
Critical Monitoring Requirements
Complete blood counts must be monitored weekly, particularly in patients receiving treatment longer than 2 weeks due to significantly increased myelosuppression risk 1
Perform visual acuity and color discrimination testing monthly in patients receiving extended treatment 1
Consider prophylactic pyridoxine in patients at risk for peripheral neuropathy (diabetes, alcohol abuse, malnutrition) 1
Monitor for thrombocytopenia (7.4% incidence), decreased hemoglobin/hematocrit (4.1%), and gastrointestinal disturbances (9.8%) 2
Critical Drug Interactions and Contraindications
Avoid concomitant use with monoamine oxidase inhibitors or within 2 weeks of discontinuing such medications 1
Exercise extreme caution with serotonergic drugs (SSRIs, SNRIs, trazodone), as linezolid has weak MAOI activity and can precipitate serotonin toxicity, typically within 1-3 days of initiation 5
Consider tapering or reducing dosages of serotonergic medications during linezolid therapy, especially when patients are on higher-end dosages 5
Avoid in patients with uncontrolled hypertension, pheochromocytoma, carcinoid tumor, thyrotoxicosis, bipolar depression, schizophrenia, or acute confusional states 1
Common Pitfalls to Avoid
Do not use linezolid empirically for catheter-related bloodstream infections; vancomycin or daptomycin are preferred first-line agents 1
Patients with CrCL ≥ 130 mL/min/1.73 m² or those on P-glycoprotein modulators require therapeutic drug monitoring to optimize dosing 3
The high interindividual pharmacokinetic variability means standard dosing may result in suboptimal or toxic concentrations in some patients, warranting consideration of therapeutic drug monitoring in complex cases 6