Prescribing and Monitoring Intravenous Amikacin in Adults

This guideline is adapted from the NHS Greater Glasgow and Clyde document, with permission.

Background

Amikacin is a protected aminoglycoside antibiotic and should only be prescribed on the advice of an infection specialist.

For glossary of terms see Glossary

Dosing

A once daily regimen is preferred as this is safer for patients and more efficient without being any less effective than a multiple daily dose regimen.

Usual dose is 15mg/kg (maximum 1·5g) once a day with a maximum of 15g per course. There is a higher risk of ototoxicity with higher cumulative doses and longer treatment courses. The dose should be adjusted according to weight and degree of renal impairment.

Creatinine Clearance (CrCl) ml/min

Amikacin Dose

20 to 29

5·5mg/kg 24hrly

30 to 49

6mg/kg 24hrly

50 to 70

12mg/kg 24hrly

Over 70

15mg/kg 24hrly

Dose adjustment in obesity

If the patient is obese (greater than 120% of their IBW), use adjusted body weight, calculated as follows:

Ideal body weight (IBW) (kg):

Male IBW = 50 + (2.3 x (height in inches – 60))

Female IBW = 45 + (2.3 x (height in inches – 60))

Adjusted Bodyweight (AdjBW) (kg):  AdjBW = IBW +0.4 (actual body weight (kg) – IBW)

Target Concentrations

 

If CrCl 50ml/min or above

If CrCl less than 50 ml/min

Peak (1 hour post dose)

Greater than 35 mg/L

15 to 30 mg/L

Trough (pre-dose)

Less than 2mg/L

Less than 5 mg/L

Monitoring

Prior to the second dose, take a trough level (immediately prior to dose) then a peak level (1 hour post dose) and then repeat these levels every 2 to 3 days thereafter.
Doses should continue to be administered whilst awaiting level as long as renal function is stable.
Samples are sent to via Raigmore Hospital Microbiology Laboratory to Bristol for analysis and are only processed Monday to Friday. Results should be available the following day but if sent on a Friday they would be back Monday at the earliest and later if a bank holiday.
Careful consideration therefore needs to be made if starting therapy on a Thursday or Friday as levels will not be available at the correct time to inform dosing. Microbiology should be involved and discussions had about the safety of treatment and whether or not an alternative therapy could be used in these situations.

References

Editorial Information

Last reviewed: 27/02/2023

Next review date: 30/11/2023

Author(s): Antimicrobial Management Team.

Version: 1

Approved By: TAM Subgroup of ADTC

Reviewer name(s): Alison Macdonald, Area Antimicrobial Pharmacist.

Document Id: AMT101