Linezolid (Zyvox) Dosing in Adult Patients
The standard recommended dose of linezolid for adult patients is 600 mg administered orally or intravenously twice daily (every 12 hours). 1, 2
Standard Dosing Recommendations by Indication
- Complicated skin and soft tissue infections: 600 mg PO/IV twice daily for 7-14 days 1, 2
- Pneumonia: 600 mg PO/IV twice daily for 7-14 days 2
- Osteomyelitis: 600 mg PO/IV twice daily for a minimum of 8 weeks 1, 2
- CNS infections:
- Infective endocarditis: 600 mg PO/IV twice daily for >6 weeks 1
Administration Considerations
- Linezolid has 100% bioavailability in both oral and intravenous formulations, making the oral route equally effective when patients can tolerate it 3
- Food slightly decreases the rate but not the extent of absorption 4
- The elimination half-life of linezolid is 5-7 hours, making twice-daily dosing appropriate 4
Special Population Considerations
- Renal impairment: No dosage adjustment is required for patients with mild to moderate renal impairment 4
- Severe renal impairment: Use with caution as exposure to the two primary metabolites is 7-8 fold higher than in patients with normal renal function 4
- Hepatic impairment: No dosage adjustment is required for patients with mild to moderate hepatic impairment 4
- Pediatric patients: Higher daily dosages per kg bodyweight are required in children due to higher clearance of linezolid compared to adults 4
- Gender differences: Higher concentrations are observed in women compared to men, but the difference is not sufficient to warrant dosage adjustment 4
Monitoring Recommendations
- Complete blood counts: Should be monitored weekly in patients receiving linezolid for more than 14 days 5
- Thrombocytopenia risk: Thrombocytopenia appears to be dependent on duration of therapy (generally >2 weeks of treatment) 6, 5
- Treatment discontinuation: Consider discontinuing treatment if there is evidence of myelosuppression 5
Drug Interactions and Precautions
- Linezolid is a mild, reversible inhibitor of monoamine oxidases A and B 4
- Foods containing high concentrations of tyramine should be avoided 5
- Use with caution in patients taking adrenergic or serotonergic agents 5
- No pharmacokinetic interaction when linezolid is coadministered with aztreonam, gentamicin, or warfarin 4
Common Adverse Effects
- Most common adverse events in adults include diarrhea, nausea, and headache 5
- Adverse events are typically mild to moderate in intensity and of limited duration 5
- Clostridium difficile-related complications with linezolid are uncommon 5
Linezolid's excellent bioavailability in both oral and intravenous formulations provides flexibility in administration routes, allowing for easy transition from IV to oral therapy when clinically appropriate 3.