1. considering further dose(s)
Starting dose
Normal renal function
5 mg/kg (max. 500 mg)
(round to nearest 40 mg)
Patient >70 years OR
estimated GFR ml/min
3 mg/kg (round to nearest 40 mg)
Significant renal impairment
Estimated GFR < 20 ml/min
2 mg/kg (round to nearest 40 mg)
Stat dose only
Level after hours
Await results before
considering further dose(s)
Day 1
Start time of 1st dose
1st dose given between
4 am and 8 pm
1st dose given between
8 pm and 4 am
Guide to Once Daily Gentamicin Dosing - NUH Clinical Haematology Unit
4am–2pm
2pm-8pm
Blood sample1 at 8 am
Blood sample1 at 2 pm
Blood sample1 at 10 pm
Day 2
Notes
A ‘pre-dose’ gentamicin level should be taken hours after the 1st dose. Target value is < 1 mg/L. Post-dose samples are not required.
The 2nd dose can be administered before the assay results are available to patients with stable renal function and good urine output.
2nd & subsequent doses2
at 2 pm (after level)
2nd & subsequent doses2
at 10 pm (after level)