Antibiotic Assays (Therapeutic Drug Monitoring)

Microbiology

Summary

Assays used to measure the concentration of certain antibiotics in the blood.

Specimen

Blood

Specimen container

There are three different types of blood tubes used for the various assays:

Clotted SST blood tube (Gold Top) 5ml

Plain clotted blood tube (Red top) 5ml

EDTA blood tube (Purple top)

The type of blood tube required is dependent on the antibiotic assay being requested – please see Full List of Antibiotic Assays for details.

How To Request On EPIC

For electronic requesting using EPIC (RDUH ONLY):

Search for: ‘”Antibiotic Name” Level‘ or the test code shown on this table: Full List of Antibiotic Assays

Special Instructions

Please send serum unless otherwise specified, and state DOSE, TIME OF LAST DOSE, and TIME SAMPLE TAKEN

Full List of Antibiotic Assays

For interpretation of levels, please refer to the Antimicrobial App or contact us to discuss

High Risk Specimens

Requests must indicate if a specimen is high risk. Please indicate details of the risk e.g. TB, MPox, Viral Haemorrhagic Fever.

For more details please see our guidance on high risk specimens.

Availability

Gentamicin, Tobramycin and Vancomycin – Processed locally in Blood Sciences at RDUH
All other antibiotics – Sent to reference laboratory (See Full List of Antibiotic Assays)

Turnaround Time

Gentamicin, Tobramycin and Vancomycin – within 24 hours
All other antibiotics – 7-10 days

Further Information

For Patients:

Therapeutic Drug Monitoring – Lab Tests Online

For Healthcare professionals:

Antimicrobial Guidance for RDUH

Antimicrobial Reference Laboratory | North Bristol NHS Trust

Analytes | North Bristol NHS Trust

Toxicology Laboratory – Cardiff and Vale University Health Board

Toxicology Laboratory Test Repertoire

(Key words: Amikacin, Netilmicin, Itraconazole, Voriconazole, Posaconazole, Teicoplanin, Acyclovir, Ciprofloxacin, Colistin, Cycloserine, Daptomycin, Ethambutol, Flucloxacillin, Fluctosine, Ganciclovir, Isoniazid, Linezolid, Penicillin, Rifampicin, Streptomycin, Co-trimoxazole, Cotrimoxazole, Sulphamethoxazole, Trimethoprim)

Specimen Labelling Procedure