Perth Children’s Hospital

Children’s Antimicrobial Management

Program (ChAMP)

MONOGRAPH

Gentamicin (intravenous) Monograph - Paediatric

Scope (Staff): Medical, Pharmacy, Nursing
Scope (Area): All Clinical Areas

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CAHS commits to being a child safe organisation by applying the National Principles for Child Safe
Organisations. This is a commitment to a strong culture supported by robust policies and procedures to
reduce the likelihood of harm to children and young people.

This document should be read in conjunction with this DISCLAIMER

QUICKLINKS

Dosage/Dosage
Administration Compatibility Monitoring
Adjustments

DRUG CLASS

Aminoglycoside antibiotic.(1)
Gentamicin is a High Risk Medicine.
INDICATIONS AND RESTRICTIONS

IV: Monitored (orange) antibiotic

 If the use is consistent with a standard approved indication, this must be communicated to
ChAMP by documenting that indication on all prescriptions (inpatient and outpatient).
 The ChAMP team will review if ongoing therapy is required and/or if the order does not meet
ChAMP Standard Indications
 If use is not for a standard approved indication, phone approval must be obtained from
ChAMP before prescribing.
CONTRAINDICATIONS

 Hypersensitivity to gentamicin, any aminoglycoside (e.g. tobramycin or amikacin) or any

component of the formulation.(2, 3)
 History of vestibular or auditory toxicity due to use of an aminoglycoside. (1) See ‘monitoring’
section
 Gentamicin (intravenous) Monograph - Paediatric

PRECAUTIONS

 Use gentamicin with caution in patients with renal impairment, reduce the dose of gentamicin
as recommended under ‘dose adjustment’ and seek infectious diseases, ChAMP or pharmacy
advice. Risk factors for nephrotoxicity include duration of treatment, high plasma
concentrations, dehydration and treatment with other nephrotoxic medications. (1)
 Use gentamicin with caution in patients with neuromuscular disease e.g. myasthenia gravis as
the risk of muscle weakness and respiratory depression is increased.(1)
 There is an increased risk of neuromuscular adverse effects when used in patients with
hypocalcaemia, hypermagnesaemia and patients undergoing general anaesthesia or receiving
large transfusions of citrated blood.(1)
 Ototoxicity (both auditory and vestibular) may occur with gentamicin use and may be
irreversible.(3)

FORMULATIONS
Listed below are products available at PCH, other formulations may be available, check with
pharmacy if required:

 80mg/2mL Vial
 5mg/mL intrathecal injection (not covered in this monograph) – SAS restrictions also apply.
Imprest location: Formulary One
DOSAGE & DOSAGE ADJUSTMENTS
Neonates: Refer to Neonatal Medication Protocols

Dosing in Overweight and Obese Children: Dosing should be based on adjusted body weight
for overweight or obese children.
IV/IM:
General once daily dosing:
 Children ≥ 1 month old to 10 years old: 7.5mg/kg/dose (to a maximum of 320mg) ONCE
daily.(1)
 Children >10 years to 18 years : 6-7mg/kg/dose (to a maximum of 560mg) ONCE daily.(1)
 No further dose increases should be made without consulting infectious diseases, ChAMP or
clinical microbiology.
Streptococcal and enterococcal endocarditis:
 All ages: 1mg/kg/dose (to a maximum dose of 80mg) given 8 hourly in combination with
other agents.(4)
 Multiple daily dosing of gentamicin is only recommended for directed therapy of confirmed
streptococcal and enterococcal endocarditis.
 Once daily dosing (as per general once daily dosing stated above) should be used for the
empiric therapy of endocarditis.(4)
 Refer to ChAMP empiric guidelines: Sepsis and Bacteraemia for further advice regarding

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 Gentamicin (intravenous) Monograph - Paediatric
recommended combination therapy. Contact infectious diseases, clinical microbiology or
pharmacy for advice.
Cystic Fibrosis:
 Tobramycin is the aminoglycoside of choice in patients with cystic fibrosis. Refer to the
ChAMP tobramycin monograph for further information.

Surgical prophylaxis:
 All patients ≥1 month old: 2mg/kg to 5mg/kg as a single dose given 15 to 60 minutes before
surgical incision.(5)
 Majority of procedures will only require a 2mg/kg dose. The 5mg/kg dose should be reserved
for cardiac procedures and procedures likely to last longer than 6 hours.(1, 5)
Refer to ChAMP surgical prophylaxis guidelines for specific recommendations.

Renal impairment:
 eGFR calculator (Google Chrome®)

 Where possible, consider using a less nephrotoxic agent.

 Dosage adjustment may be required in cases of impaired renal function (with creatinine
clearance of less than 60mL/min).(4, 5)
 All patients with renal impairment should have monitoring based on AUC. See monitoring
section for further information.
 In cases where gentamicin is required, suggested initial dosing intervals are stated below. All
future doses and intervals are to be determined based on therapeutic drug monitoring.
o CrCl > 60mL/minute: 24 hourly dosing interval
o CrCl 40-60mL/minute: 36 hourly dosing interval
o CrCl < 40 mL/minute: consider alternative agents. If essential, give initial dose then
contact Pharmacy for advice on monitoring and further doses.(5, 6)
Hepatic impairment:
 No dosage adjustment is required.(2)
ADMINISTRATION

IV Injection:
 For doses ≤ 120mg, the dose may be diluted to a suitable final volume (up to 20mL) with
compatible fluid and administered over 3 to 5 minutes.(7)
 For critically unwell patients, higher doses may be given via a push over 3 to 5 minutes.
IV infusion:
 Dilute to a suitable volume (up to 100mL) with compatible fluid to allow infusion over 30
minutes. (7, 8)
IM injection:
 If IV access is not available this medication may be given by IM injection into a large muscle

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 Gentamicin (intravenous) Monograph - Paediatric
mass. However the IV route is preferred for patients with suspected shock or sepsis.
 IM injection is NOT suitable for premature neonates.(2)
 Refer to Intramuscular (IM) injections for further information.
COMPATIBILITY
Compatible fluids:

 Sodium chloride 0.9%

 Glucose 5%
 Glucose 10%
 Glucose/sodium chloride solutions
 Hartmann’s(7)
Compatible at Y-site:
Compatibilities of IV drugs must be checked when two or more drugs are given concurrently.
MONITORING

Therapeutic drug monitoring:

Monitoring in Neonates:
 Please refer to Neonatal Medication Protocols
Monitoring for patients with normal pharmacokinetics:
 Trough level should be taken immediately prior to the 4th dose and should be below the limit of
detection (<0.6mg/L).
 If the trough level is greater than or equal to 0.6mg/L, contact Pharmacy for advice as this
indicates reduced clearance of gentamicin and cessation or dose adjustment is required.
 Follow-up levels should be performed twice weekly unless the clinical situation dictates
otherwise (e.g. impaired renal function and concurrent use of nephrotoxic drugs where levels
should be collected more frequently).
Patients with altered pharmacokinetics:
 Includes patients with Cystic fibrosis, oncology patients, patients with severe burns or patients
with impaired renal function.
 These patients should have therapeutic drug monitoring completed with the SECOND dose of
gentamicin.
 Monitoring should be based on calculating the drug concentration in the body relative to time,
monitoring area under the curve (AUC).
 AUC measurement involves a mathematical calculation that requires the recording of the drug
concentration at two specific times.
 Refer to the form MR860.91 Gentamicin and Tobramycin AUC Reporting Form for the specific
times required.
 This form should be kept in the patients notes on the ward and it will be collected and

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 Gentamicin (intravenous) Monograph - Paediatric
interpreted by the ward pharmacist who will then calculate the AUC.
 The target AUC for Oncology patients is 60-80mg/L.hr
 ALL patients (including those on HiTH) require ongoing monitoring of their gentamicin AUC
levels at a minimum of once weekly AND/OR following any dose adjustment.
HiTH patients (excluding those with altered pharmacokinetics):
 Require weekly monitoring of their trough levels and renal function monitoring.
 Trough levels should remain below the limit of detection (<0.6mg/L).
 If the trough level is greater than or equal to 0.6mg/L, contact Pharmacy for advice as this
indicates reduced clearance of gentamicin and cessation or dose adjustment is required.
Process of therapeutic drug monitoring:
 Blood samples for therapeutic drug monitoring (TDM) for gentamicin may be collected via a
capillary blood sample OR via accessing a central venous access device (CVAD) line.
 A capillary blood sample (i.e. finger prick or heel prick for infants <6months) should be used if
there is no CVAD in-situ.
 For patients with a CVAD in-situ the following process should be used:(9)
o Stop all fluids running through the CVAD line.
o Flush the line with sodium chloride 0.9%. The volume used is three times the internal
line-filling volume of the CVAD device (as per table below).
o Collect an initial blood sample to be discarded. The volume taken is three times the
internal line-filling volume of the CVAD device PLUS the additional volume of the IV
tubing, injection caps and connectors (as per table below). This is to ensure there is no
residue gentamicin in the line which may falsely elevate levels.
o Collect a therapeutic drug level monitoring sample of blood to send to PathWest for
determination of the AUC.
o Administer another flush of sodium chloride 0.9% (volume as per table below) to ensure
line does not clot after blood sample is taken.
o Recommence fluids if required
Line type Approximate internal Flush and discard
fill volume of CVAD volume
and line

PICC and Non-tunnelled CVC 1mL 3mL

Tunnelled line (broviac) and 2mL 6mL

Implanted (port)

Collection tube:
 Paediatric – Serum, no gel (RED), Lithium heparin, no gel (DRGNLITH) or Lithium heparin-
PST (GREEN) (10)

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 Gentamicin (intravenous) Monograph - Paediatric
 Minimum volume required: 300microlitres(10)
For further information, refer to the PathWest test directory.

Additional monitoring:
 Renal function and electrolytes should be performed weekly whilst on treatment.
 Patients receiving treatment > 2 weeks with gentamicin (e.g. for osteomyelitis or endocarditis)
must be monitored for hearing loss and vestibular toxicity every 1 to 2 weeks. (1)
ADVERSE EFFECTS
Common: Nephrotoxicity (usually reversible, but can be anticipated if treatment extends beyond
7-10 days, or if pre-existing renal impairment). Clinically evident vestibular ototoxicity (nausea,
vomiting, vertigo, nystagmus, difficulties with gait) and cochlear ototoxicity (noticeable hearing
loss, tinnitus, a feeling of fullness in ear) occur in 2–4% of patients. Ototoxicity may be delayed in
onset and may be irreversible.(1, 11)
Infrequent: nausea, vomiting, skin reactions(11)
Rare: Anaphylaxis, bronchospasm, oliguria, peripheral neuropathy and neuromuscular blockade,
electrolyte disturbances (e.g. hypomagnesaemia),, anaemia, azotaemia, eosinophilia, fever,
headache, paraesthesia.(1, 11)
STORAGE

 80mg/2mL ampoule should be protected from light and stored below 25˚C. (7)

INTERACTIONS
This medication may interact with other medications; consult PCH approved references (e.g.
Clinical Pharmacology), a clinical pharmacist or PCH Medicines Information Service on extension
63546 for more information.
**Please note: The information contained in this guideline is to assist with the preparation and administration
of gentamicin (intravenous). Any variations to the doses recommended should be clarified with the
prescriber prior to administration**

Related CAHS internal policies, procedures and guidelines

Antimicrobial Stewardship Policy

ChAMP Empiric Guidelines and Monographs

KEMH Neonatal Medication Protocols

References

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 Gentamicin (intravenous) Monograph - Paediatric
1. Rossi S, editor. Australian Medicines Handbook. Adelaide, S. Aust.: Australian Medicines Handbook; 2021.
2. Clinical Pharmacology [Internet]. Elsvier BV. 2021 [cited 8/07/2021]. Available from:
http://www.clinicalpharmacology-ip.com.pklibresources.health.wa.gov.au/default.aspx.
3. MIMS Australia. MIMS online [full product information]. St Leonards, N.S.W: CMP Medica Australia.; 2021. p.
1v. (various pagings).
4. Royal Australian College of General Practitioners, Pharmaceutical Society of Australia, Australasian Society
of Clinical and Experimental Pharmacologists and Toxicologists. AMH: Children's Dosing Companion. Adelaide:
Australian Medicines Handbook Pty Ltd; 2020.
5. Antibiotic Writing Group. eTG complete. West Melbourne: Therapeutic Guidelines Ltd; 2021. Available from:
https://tgldcdp-tg-org-au.pklibresources.health.wa.gov.au/etgAccess.
6. IBM Micromedex [Internet]. Truven Health Analytics. 2021 [cited 11/05/2021]. Available from: http://www-
micromedexsolutions-com.pklibresources.health.wa.gov.au/micromedex2/librarian.
7. Symons K. Ermer J. (editors). Australian injectable drugs handbook. Collingwood: The Society of Hospital
Pharmacists of Australia; 2020.
8. Pediatric Injectable Drugs. Maryland: American Society of Health -System Pharmacists; 2020.
9. Lichliter RL, Tremewan LE, Shonka NM, Mehnert JE, Brennan L, Thrasher JM, et al. Therapeutic antibiotic
serum concentrations by two blood collection methods within the pediatric patient: A comparative effectiveness trial. J
Spec Pediatr Nurs. 2018;23(2):e12212.
10. PathWest. PathWest - test directory Perth2021 [cited 2021. Available from:
http://www.pathwest.com.au/testdirectory/.
11. Paediatric Formulary Committee. BNF for Children: 2020. London: BMJ Group Pharmaceutical Press; 2021.

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File Path: W:\Paediatrics\PMH\ChAMP\Monographs\FINALISED\00 Current version 00

Document Owner: Head of Department – Infectious Diseases
Reviewer / Team: Children’s Antimicrobial Management Program Pharmacist
Date First Issued: April 2013 Last Reviewed: August 2021
Amendment Dates: December 2017 Next Review Date: August 2024
Approved by: Medication Safety Committee Date: August 2021
Endorsed by: Chair, Drugs and Therapeutics Committee Date: September 2021
Standards
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NSMHS: N/A
Child Safe Standards: N/A
Printed or personally saved electronic copies of this document are considered uncontrolled

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