Last updated: Wednesday, 12, September, 2007
MBS Online Search Page: Click here for details
At least 1 mL blood in plain tube.
| Reference Interval|
Depends on antibiotic and dose regimen.
Monitoring plasma levels of potentially toxic drugs such as aminoglycosides, vancomycin, flucytosine and, in neonates, chloramphenicol.
For once-daily dosage of gentamicin, tobramycin or amikacin: a single measurement of plasma concentration should be made 6-14 hours after a dose.
If the measured concentration of gentamicin or tobramycin, or one quarter the measured concentration of amikacin, does not lie between the curves on the graph then dose adjustment is required.
For 8- and 12- hourly dosage of aminoglycosides, a peak level is measured to assess adequacy of the dose in serious infections.
The peak level should be measured 30 minutes to 1 hour after a dose, given either as an IV infusion over 20-30 minutes or as an IM injection.
A trough level (immediately prior to the next dose) is measured to assess whether accumulation is occurring.
The following are recommended levels for 8-12 hourly Aminoglycoside Therapy:
For vancomycin, peak levels do not correlate with either efficacy or toxicity. Trough levels should be maintained at 10-20mg/L.
Flucytosine toxicity occurs at levels >100 mg/L. Trough levels should be maintained at >25 mg/L for efficacy.
Victorian Drug Usage Advisory Committee. Antibiotic Guidelines. 13th ed. 2006