Gentamicin in haemodialysis (Guidelines)

TAM (Treatments and Medicines) NHS Highland
NHS Highland

Audience

  • All NHS Highland
  • Primary and secondary care
  • Adults only

** DO NOT USE THE GENTAMICIN CALCULATOR OR THE PRE-PRINTED GENTAMICIN PRESCRIBING CHARTS FOR PATIENTS RECEIVING HAEMODIALYSIS/HAEMODIAFILTRATION **

This policy covers the use of gentamicin in patients receiving haemodialysis / haemodiafiltration (HDF)

Administration of gentamicin to patients on haemodialysis is complicated by removal of gentamicin by dialysis.  Given that gentamicin is removed by haemodialysis it appears to be safe to give gentamicin when pre dialysis levels are 4mg/L or less.  Gentamicin should be given at the end of the dialysis session.

Do NOT convert patients to low flux haemodialysis as gentamicin is removed by both high and low flux haemodialysis

Contraindications:

  • Myasthenia gravis, hypersensitivity

Cautions:

  • Gentamicin nephrotoxicity may harm residual renal function (consider alternatives, particularly for patients on incremental dialysis)
  • Concurrent administration of neurotoxic and/or nephrotoxic agents increases the risk of gentamicin toxicity. Review therapy and consider amending or withholding nephrotoxic drugs during gentamicin treatment.
  • Avoid co-administration with the following:
    • neuromuscular blockers
    • other potentially nephrotoxic (e.g. NSAIDs and ACE Inhibitors) or ototoxic drugs
    • potent diuretics such as furosemide
    • other aminoglycosides
      This list is not exhaustive – consult the Summary of Product Characteristics for a full list (medicines.org.uk)

Ototoxicity

  • Ototoxicity secondary to gentamicin is independent of drug concentration. It is suggested by any of the following symptoms developing whilst on therapy:
    • new tinnitus
    • dizziness
    • poor balance
    • hearing loss
    • oscillating vision
  • Toxicity is associated with prolonged aminoglycoside use (usually more than 10 days but may be more than 72 hours) and is secondary to drug accumulation within the inner ear. Any changes in hearing or vision are best reported by the patient – give NHS Highland leaflet “Gentamicin – your hearing and balance” available on TAM. Ask about any new symptoms before each dose administration.
  • Stop treatment if ototoxicity is suspected and refer to microbiology or an infection specialist for advice on future therapy. Consider referral to ENT for assessment and management.
  • If gentamicin continues for more than 7 days, consider referring to audiology for assessment. If the anticipated course will be more than 7 days, consider baseline audiology, if available.

Prescribing and documentation

Gentamicin for dialysis patients should usually be prescribed on HERMES.  If the dose is to be given out of hours it may be prescribed as a one-off dose on the drug chart/HEPMA but the prescription should be reviewed by a member of the renal MDT before a second dose is prescribed  

Gentamicin for dialysis patients should NOT be prescribed on the pre-printed gentamicin prescription and administration charts.

Step 1: calculating dose

Dose

Use dry weight, especially if patients have oedema. 

If patient overweight use ‘maximum body weight’ as per the table maximum-body-weight-table.pdf.

Initial dose: 2mg/kg (rounded to nearest 20mg)

 

Patient weight or 'maximum body weight'
 

40 to 49kg

 50 to 59kg 60 to 69kg 70 to 79kg 80 to 89kg >90g
Dose

80mg

 100mg 120mg 140mg 160mg 180mg

Administration:

Give gentamicin as bolus injection over 3 to 5 minutes at the end of dialysis, during the wash back.  The prescribed dose of gentamicin should be given via the venous port of the dialysis machine. The wash back time can be extended until administration of the bolus is achieved over the appropriate time scale. 

Please refer to Injectable Medicines Guide (Medusa) for further advice: Medusa Homepage

Step 2: Monitor gentamicin levels

If gentamicin is to be given as a one-off dose, therapeutic drug monitoring is NOT required. 

If gentamicin is to continue, a trough level should be taken as follows. 

Dialysis days:

  • Take a level BEFORE the start of dialysis.

Level

Advice

<4mg/L
(note caution below)

 Re-dose at original dose at the end of the dialysis session

>4mg/L

 Do NOT give. Inform the ward pharmacist or medical staff

Non-dialysis days:

If patient is NOT dialysing but could be due a further dose i.e. it will be >48 hours until their next dialysis session.

  • Take a level BEFORE the expected dosing time (usual).
  • Re-dose at original dose if level is <2mg/L (or <1mg/L if for infective endocarditis synergistic dosing). 
  • If patient is NOT on dialysis the dose will require to be prescribed on the drug chart / HEPMA as a one-off dose. 
  • Ensure renal team are made aware. 
If unsure, please contact renal pharmacist (bleep 2025) or a Renal Consultant for advice

Caution

Caution is required in patients who have had a poor/incomplete dialysis treatment as gentamicin may not have been fully removed.  Withhold gentamicin and alert medical staff if a patient has completed less than 2 hours of dialysis OR had poor-quality dialysis e.g. a blood flow of under 150mL/min, repeated conductivity alarms etc.

Step 3: Assess the daily need for gentamicin and signs of toxicity

To minimise the risk of toxicity, duration of treatment should normally be limited to 72 hours. All gentamicin prescriptions that continue beyond 3 to 4 days of treatment must be discussed with microbiology or an infection specialist.

Abbreviations

  • ENT: ear nose and throat
  • MDT: multi-disciplinary team
  • NSAIDs: non-steroidal anti-inflammatory drugs

Editorial Information

Last reviewed: 28/08/2025

Next review date: 28/08/2028

Author(s): Renal department.

Version: 1

Approved By: TAM subgroup of the ADTC

Reviewer name(s): K McCulloch, Renal Pharmacist.

Document Id: TAM705