Linezolid Half-Life
The elimination half-life of linezolid is approximately 4.5 to 5 hours in adults, allowing for twice-daily dosing. 1
Pharmacokinetic Parameters
The half-life of linezolid varies slightly across different populations and clinical contexts:
Adult Populations
- Standard adult half-life: 4.5 hours as documented in IDSA guidelines for outpatient parenteral antimicrobial therapy 1
- Range of 4-6 hours reported in vancomycin comparison studies 1
- Measured plasma half-life of 4-5 hours in pharmacology reviews, which permits twice-daily administration for all indicated infections 2
- Elimination half-life of 5-7 hours in comprehensive pharmacokinetic analyses 3
- FDA-approved labeling reports 4.9 hours (range 1.8-8.3 hours) in adult subjects 4
Special Populations
Pediatric patients demonstrate age-dependent variations in half-life 4:
- Preterm neonates <1 week: 5.6 hours (range 2.4-9.8 hours)
- Full-term neonates <1 week: 3.0 hours (range 1.3-6.1 hours)
- Full-term neonates ≥1 week to ≤28 days: 1.5 hours (range 1.2-1.9 hours)
- Infants >28 days to <3 months: 1.8 hours (range 1.2-2.8 hours)
- Children 3 months through 11 years: 2.9 hours (range 0.9-8.0 hours)
- Adolescents 12-17 years: 4.1 hours (range 1.3-8.1 hours)
Critically ill patients with renal failure undergoing continuous venovenous hemofiltration (CVVH) show a half-life of 4.3 ± 1.7 hours, comparable to healthy subjects 5
Patients with renal insufficiency do not experience altered linezolid half-life, though metabolites accumulate 4:
- Moderate renal impairment (CLCR 30-80 mL/min): 6.1 hours
- Severe renal impairment (CLCR 10-30 mL/min): 7.1 hours
- Hemodialysis-dependent (off dialysis): 8.4 hours
- Hemodialysis-dependent (on dialysis): 7.0 hours
Clinical Implications
The 4.5-5 hour half-life supports the standard dosing regimen of 600 mg every 12 hours for adults with serious infections including MRSA bacteremia, nosocomial pneumonia, and complicated skin infections 1, 6
Pediatric patients require more frequent dosing (every 8 hours) due to faster clearance and shorter half-lives in younger age groups, with the exception of adolescents who follow adult dosing 4
No dosage adjustment is required based on half-life changes in renal or hepatic impairment, as the parent drug pharmacokinetics remain stable despite metabolite accumulation 4, 3