Test Name

Linezolid

Test Code

SALINE 

Specimen Type

Plasma - EDTA   

Preferred Volume   3mL

Minimum Volume  1mL (Capillary samples is acceptable -2x 0.5mL)

Comments

Linezolid therapeutic drug monitoring

Linezolid is a synthetic antimicrobial agent, an oxazolidinone. It inhibits bacterial growth by binding to the 50 S ribosomal subunits and inhibiting protein synthesis. Linezolid is a bacteriostatic antimicrobial.

The main activity of linezolid is against gram-positive organisms with no activity against gram-negative organisms. It has also been shown to be active against mycobacteria species and nocardia species. There is also some activity against tuberculosis. For administration see Alfred Health guideline on prescribing and monitoring Linezolid Prescribing and Monitoring .

Significant side-effects include myelosuppression, peripheral neuropathy, optic nerve toxicity and lactic acidosis.

Therapeutic drug monitoring should be considered for Linezolid in patients on prolonged therapy, with renal or liver impairment, patients with critical illness such as in the intensive-care unit and for other physiological extremes (e.g. extreme overweight or malnutrition).

Suggested therapeutic levels

Measure trough levels at least 48-hours following initiation or dose change of linezolid.

Recommended: 2-7 mg/L or 4 X minimum inhibitory concentration (MIC) of organism

Potentially toxic: > 7 mg/L

Due to the risk of serious adverse effects the use of linezolid beyond 28 days is not recommended and should be discussed with the infectious diseases registrar.. 

LAB NOTES:

Centrifuge, separate and freeze plasma.

Send to testing laboratory on dry ice. Do not pack dry ice in a sealed container. Use appropriate PPE.

Assay Performed

Biochemistry Dept

Alfred Hospital

Commercial Road

Prahran 3181

VIC

03 9076 3888

Assay Frequency

Weekly