Pdf is being generated, will be available at /media/pdfs/references-38.pdf shortly

Aminoglycoside & Vancomycin Dosing & Monitoring (Adults)

Download / Print Section as PDF

Cockcroft and Gault Equation

Cockcroft and Gault Equation

Creatinine Clearance (CrCl) (ml/min)

  • Calculate Ideal Body Weight (IBW) in kg (see below)

(140 – age) x (IBW in kg) x N

Serum creatinine (micromol/L)

1. N = 1.23 males & 1.04 females

2. If actual body weight < IBW, use actual body weight in this equation

Ideal Body Weight (IBW) (kg) =

Male:

50kg + (2.3 x inches over 5 feet) OR 50kg + (0.9 x cm over 152cm)

Female:

45.5kg + (2.3 x inches over 5 feet) OR 45.5kg + (0.9 x cm over 152cm)

Download / Print Section as PDF

Amikacin Dosing & Monitoring

Amikacin Dosing & Monitoring

  1. Effective use of amikacin is complex and should be discussed with Microbiology. The following is provided for guidance.
  2. In general, treatment should be reviewed within 24 hours, and daily thereafter by consultant/registrar. Courses should not usually exceed 3 days. The recommended maximum daily dose is 1.5g; the maximum cumulative dose should not exceed 15g per treatment course.
  3. In multi-drug resistant TB (on Respiratory or Microbiology advice), discuss with Microbiology or Pharmacy for dosing and monitoring guidance.
  4. In patients with impaired renal function (creatinine clearance less than 80ml/minute) a void aminoglycosides if possible. If amikacin is being considered discuss with Microbiology.
  5. Amikacin is potentially nephrotoxic & ototoxic; monitor amikacin levels closely.
  6. Prolonged duration of treatment and co-administration of nephrotoxins (e.g. diuretics, NSAIDs, vancomycin) increases risk of toxicity and should be avoided where possible.
  7. The responsible clinical team must check reported amikacin levels regularly and adjust dosing if required. The laboratory does NOT alert teams of out of range results. Levels must arrive in the microbiology laboratory by 11am Monday to Friday and by 10am Saturday (not processed on Sunday) to be analysed on the day of receipt.
  8. Do NOT hold dose while waiting for level to be reported, in a patient less than 65 years with good renal function (creatinine clearance greater than 80ml/minute) and with good urine output.
  9. However, in a patient over 65 years, or with abnormal renal function (creatinine clearance less than 80ml/minute), it is generally preferable to await the result of the first amikacin level (i.e. before the second dose) before giving the next dose. If the level is less than 1mg/L and renal function is stable it is not necessary to routinely hold subsequent doses pending levels.
  10. Once daily dosing of amikacin is recommended for most patients. Discuss patients with renal impairment (creatinine clearance less than 30ml/minute) with Microbiology for advice on a case-by-case basis.

Table 1: Once Daily Amikacin Dosing Guidelines (Except TB*)

Step 1

Cautions/

Discuss with Micro or Pharmacy

· Cautions: Age ≥65, renal impairment (CrCl <80ml/min), obesity (use adjusted dosing weight), other nephrotoxins

· Patients with severe renal impairment (CrCl <30ml/min) should be discussed with Microbiology

· TB: Discuss with Respiratory, Microbiology or Pharmacy for guidance on dosing & monitoring in TB patients

Step 2

Calculate patient’s ideal body weight (IBW):

Height required

Ideal Body Weight (IBW) (kg) =

Male: 50kg + (2.3 x inches over 5 feet) OR

50kg + (0.9 x cm over 152cm)

Female: 45.5kg + (2.3 x inches over 5 feet) OR

45.5kg + (0.9 x cm over 152cm)

Step 3

Dosing Weight/

Obesity Adjustment:

Weight required

Obesity adjustment :

· Obese patient: If actual body weight exceeds IBW by ≥20%, calculate Adjusted Dosing Weight:

Adjusted Dosing Weight (kg)  =

Ideal Body Weight + 0.4 x (Actual Body Weight – Ideal Body    Weight)

· Non-obese patient: Use actual body weight to dose amikacin.

Step 4

Estimate renal function:

Patient age, weight, height, & serum creatinine required

· Must use creatinine clearance ( not eGFR) to dose amikacin.

· Calculate the patient’s estimated creatinine clearance using Cockcroft & Gault equation.

· Neither creatinine clearance nor eGFR provide a perfect marker of renal function, particularly if rapidly changing renal function.

Step 5

Select a dose based on renal function and weight. If obese use Adjusted Dosing Weight; If non-obese use Actual Body Weight (See Step 3).

CrCl (ml/min)

Dose: round to nearest 50mg

Greater than 80

15mg per kg IV (up to a max of 1.5g)

every 24 hours

60 to 79

12mg per kg IV (up to a max of 1.5g)

every 24 hours

40 to 59

7.5mg per kg IV (up to a max of 1.5g)

every 24 hours

30 to 39

4mg per kg IV (up to a max of 1.5g)

every 24 hours

less than 30

Avoid if possible.

If essential, give 3 to 4mg per kg IV (up to a max of 320mg), one dose only

Check level at 24 hours, discuss need for second dose with Micro

Intermittent haemodialysis: 5mg/kg (up to a max of 400mg) with each dialysis. Give dose post-dialysis.

*For the treatment of TB discuss with Respiratory, Microbiology or Pharmacy for guidance on dosing

Table 2: Once Daily Amikacin Administration & Monitoring Guidelines

Administration

  • See product SPC and IV administration guide on ward

  • Give first dose immediately.

Monitoring

The following applies to indications other than TB:

  • Measure pre-dose (trough) levels only.

  • Post-dose (peak) levels not routinely measured EXCEPT in TB.

  • The first pre-dose level should be taken before the 2 nd dose.

  • Take sample within the hour before dose is due.

  • Document on request form date and time sample was taken and date and time of last dose.

  • If the level is less than 5mg/L, re-check pre-dose levels twice per week thereafter, or more often if impaired or rapidly changing renal function, haemodynamically unstable, elderly, or on diuretic therapy

  • Note that monitoring of renal function in addition to monitoring of aminoglycoside levels is important as toxicity may occur in patients in whom the aminoglycoside levels have never exceeded the acceptable range.

  • With respect to ototoxicity, vestibular disturbance (vertigo, ataxia) often precedes disturbance of hearing and should not be discounted because the patient has levels within the acceptable range.

Table 3: Interpretation of Pre-dose Levels for Once Daily Amikacin

Target pre-dose (trough) level is <5mg/L

Level

Advice

<5 mg/L

  1. Is amikacin still needed?

  2. Is patient responding clinically?

  3. Continue same dose.

  4. Check level in 3 days.

≥5 mg/L

  1. Is amikacin still needed?

  2. Is it a true pre-dose (trough) (taken within one hour before dose)?

  3. Where was sample taken from? (falsely high levels can occur if taken from same line used to give amikacin).

  4. Is dose correct for weight & renal function?

  5. Is renal function stable?

  6. Dose adjustment required - contact Microbiology to discuss on a case-by-case basis.

Download / Print Section as PDF

Tobramycin Dosing & Monitoring

Tobramycin Dosing & Monitoring

  1. Effective use of tobramycin is complex and should be discussed with Microbiology. The following is provided for guidance.
  2. In general, treatment should be reviewed within 24 hours, and daily thereafter by consultant/registrar. Courses should not usually exceed 3 days, except in cystic fibrosis.
  3. In patients with impaired renal function (creatinine clearance less than 80ml/minute) a void aminoglycosides if possible. If tobramycin is being considered discuss with Microbiology.
  4. Tobramycin is potentially nephrotoxic & ototoxic; monitor tobramycin levels closely.
  5. Prolonged duration of treatment and co-administration of nephrotoxins (e.g. diuretics, NSAIDs, vancomycin) increases risk of toxicity and should be avoided where possible.
  6. The responsible clinical team must check reported tobramycin levels regularly and adjust dosing if required. The laboratory does NOT alert teams of out of range results. Levels must arrive in the microbiology laboratory by 11am Monday to Friday and by 10am Saturday (not processed on Sunday) to be analysed on the day of receipt.
  7. Do NOT hold dose while waiting for level to be reported, in a patient less than 65 years with good renal function (creatinine clearance greater than 80ml/minute) and with good urine output.
  8. However, in a patient over 65 years, or with abnormal renal function (creatinine clearance less than 80ml/minute), it is generally preferable to await the result of the first tobramycin level (i.e. before the second dose) before giving the next dose. If the level is less than 1mg/L and renal function is stable it is not necessary to routinely hold subsequent doses pending levels.
  9. Once daily dosing of tobramycin is recommended for most patients. Discuss patients with renal impairment (creatinine clearance less than 30ml/minute) with Microbiology for advice on a case-by-case basis.

Table 1: Once Daily Tobramycin Dosing Guidelines (Cystic Fibrosis only)

Dose (Cystic Fibrosis only)

· 10mg/kg (if renal function is normal) as a single dose every 24 hours, up to a maximum of 700mg in adults (660mg in children less than 18 years)

Obesity

· If actual body weight exceeds ideal body weight by ≥ 2 0%, an adjusted dosing weight should be used to calculate the dose

Renal Impairment

· Contact Microbiology for advice

Table 2: Once Daily Tobramycin Dosing Guidelines (other than Cystic Fibrosis)

Use the Tobramycin Dosing Calculator in the LAPP App to calculate Once Daily Tobramycin dose (5mg/kg in normal renal function) in non-CF patients.

Do NOT use the calculator for patients with Cystic Fibrosis, as an alternative dosing regimen is recommended.

Step 1

Cautions/

Discuss with Micro

  • Cautions: Age ≥65, renal impairment (CrCl <80ml/min), obesity (use adjusted dosing weight), other nephrotoxins.

  • Patients with severe renal impairment (CrCl <30ml/min) should be discussed with Microbiology.

Step 2

Calculate patient’s ideal body weight (IBW):

Height required

Ideal Body Weight (IBW) (kg) =

Male: 50kg + (2.3 x inches over 5 feet) OR

50kg + (0.9 x cm over 152cm)

Female: 45.5kg + (2.3 x inches over 5 feet) OR

45.5kg + (0.9 x cm over 152cm)

Step 3

Dosing Weight/

Obesity Adjustment:

Weight required

Obesity adjustment :

  • Obese patient: If actual body weight exceeds IBW by ≥20%, calculate Adjusted Dosing Weight:

Adjusted Dosing Weight (kg) =

Ideal Body Weight + 0.4 x (Actual Body Weight – Ideal Body Weight)

  • Non-obese patient: Use actual body weight to dose tobramycin.

Step 4

Estimate renal function:

Patient age, weight, height, & serum creatinine required

  • Must use creatinine clearance ( not eGFR) to dose tobramycin.

  • Calculate the patient’s estimated creatinine clearance using Cockcroft & Gault equation.

  • Neither creatinine clearance nor eGFR provide a perfect marker of renal function, particularly if rapidly changing renal function.

Step 5

Select a dose based on renal function and weight. If obese use Adjusted Dosing Weight; If non-obese use Actual Body Weight (See Step 3).

Do NOT use this table for patients with Cystic Fibrosis

CrCl (ml/min)

Dose: round to nearest multiple of 40mg

NB: Doses above 400 mg once daily rarely needed

Greater than 80

5mg per kg IV

every 24 hours

60 to 79

4mg per kg IV

every 24 hours

40 to 59

3.5mg per kg IV

every 24 hours

30 to 39 2.5mg per kg IV every 24 hours

less than 30

Avoid if possible.

If essential, give 2mg per kg IV (up to a max of 160mg), one dose only

Check level at 24 hours, discuss need for second dose with Micro

Intermittent haemodialysis: 1mg/kg (up to a maximum of 80mg) with each dialysis. Give dose post-dialysis.

Table 3: Once Daily Tobramycin Administration & Monitoring Guidelines

Administration

· See product SPC and IV administration guide on ward

· Give first dose immediately.

Monitoring

· Measure pre-dose (trough) levels only.

· The first pre-dose level should be taken before the 2 nd dose.

· Take sample within the hour before dose is due.

· Document on request form date and time sample was taken and date and time of last dose.

· If the level isless than 1mg/L, re-check pre-dose levels twice per week thereafter (once weekly in cystic fibrosis patients), or more often if impaired or rapidly changing renal function, haemodynamically unstable, elderly, or on diuretic therapy

· Note that monitoring of renal function in addition to monitoring of aminoglycoside levels is important as toxicity may occur in patients in whom the aminoglycoside levels have never exceeded the acceptable range.

· With respect to ototoxicity, vestibular disturbance (vertigo, ataxia) often precedes disturbance of hearing and should not be discounted because the patient has levels within the acceptable range.

Table 4: Interpretation of Pre-dose Levels for Once Daily Tobramycin

Target pre-dose (trough) level is <1mg/L

Level

Advice

<1 mg/L

1. Is tobramycin still needed?

2. Is patient responding clinically?

3. Continue same dose.

4. Check level in 3 days.

≥1 mg/L

1. Is tobramycin still needed?

2. Is it a true pre-dose (trough) (taken within one hour before dose)?

3. Where was sample taken from? (falsely high levels can occur if taken from same line used to give amikacin).

4. Is dose correct for weight & renal function?

5. Is renal function stable?

6. Dose adjustment required - contact Microbiology or Infectious Diseases or Pharmacy to discuss on a case-by-case basis.

Download / Print Section as PDF

Intravenous Vancomycin Dosing & Monitoring

Intravenous Vancomycin Dosing & Monitoring

1. Overview

  • Vancomycin use is complex – discuss with Microbiology or Pharmacy when unsure.
  • The following is provided for guidance:

Table 1 – Dosing Guidelines

Table 2 – Administration & Monitoring

Table 3 – Interpretation of Levels

2. Prescribing Responsibilities

  • The clinical team is responsible for checking levels and adjusting dosing.
  • Laboratory does NOT alert teams of out-of-range levels.
  • Levels available daily: 8:00am – 8:00pm
  • Do not hold doses for levels unless:
    • Specifically advised
    • Suspected toxicity
    • Renal function deteriorating

Table 1 – Vancomycin Dosing Guidelines

Table 1: Vancomycin Dosing Guidelines

Use the IV Vancomycin Dosing Calculator in the LAPP App to calculate the initial dose of vancomycin. Alternatively use the steps below to calculate the initial Loading Dose and then Maintenance Dose for Vancomycin. Please ensure these are prescribed in the correct section of the LUH MPAR/kardex (page 3).

Step 1

Calculate estimated renal function

Note: Neither creatinine clearance nor eGFR provide a perfect marker of renal function, particularly if rapidly changing renal function.

Step 2

Calculate a Loading Dose (if required)

  • A loading dose should always be considered for patients critically unwell, oncology/haematology patients or as advised by Microbiology.
  • The initial loading dose is 25mg/kg by IV infusion.
  • Use actual body weight to calculate the dose (up to a maximum of 2g)
  • Round dose to nearest multiple of 250mg.

Step 3

Select an initial maintenance dose based on renal function and actual body weight

Creatinine Clearance: (ml/minute)

Dose:
(Please round to nearest multiple of 250mg)

Frequency:

Greater than 50

15mg per kg IV (max 2g)

Every 12 hours

20 to 50

15mg per kg IV (max 2g)

Every 24 hours

less than 20

15mg per kg IV (max 2g)

Re-dose based on levels, generally every 3 to 7 days; discuss with Microbiology or Infectious Diseases or Pharmacy

Intermittent haemodialysis: See Haemodialysis Dosing Guidelines

Table 2 – Vancomycin Administration & Monitoring

Table 2: Vancomycin Administration and Monitoring Guidelines

Administration

  • Administer by IV Infusion at a maximum rate of 10mg/min (otherwise risk of anaphylactoid reactions, thrombophlebitis and vancomycin infusion reaction).
  • Follow product SPC and Medinfo GUH IV administration guide .
  • Do not delay administration of the first dose.
  • Consider giving subsequent doses at 10am and 10pm for twice daily dosing.
  • Do not hold doses pending levels or if levels have not been sent, unless specifically requested or toxicity suspected.

Monitoring

  • Obtain the first pre-dose (trough) level before the 4 th or 5 th dose .
  • Take sample within the hour before dose is due.
  • Consider sending an earlier sample in elderly patients or patients with impaired renal function.
  • Complete the laboratory request form for checking a level when prescribing the first dose, document on request form the date and time sample was taken AND date and time of last vancomycin dose.
  • If the level is acceptable check a pre-dose level within the hour before dose is due twice per week thereafter, or more often if:
    • Renal impairment
    • Haemodynamically unstable
    • Elderly
    • Or if there has been difficulty in maintaining sufficiently high levels
  • Post-dose (peak) levels should only be checked when recommended by Microbiology.
  • Regularly monitor renal function alongside vancomycin levels.

Table 3 – Interpretation of Vancomycin Levels

Table 3: Interpretation of Vancomycin Levels

What is the Target level?

The Target pre-dose (trough) level is 10 to 15mg/L, however a higher target of 15 to 20mg/L is recommended for complicated infections e.g. endocarditis, osteomyelitis, bloodstream infection, meningitis, or MRSA pneumonia.

If target level is 10 to 15mg/L

If target level is 15 to 20mg/L

Level

Advice

Level

Advice

< 10mg/L

Low

  1. Is vancomycin still needed?
  2. Is it a true pre-dose trough level (taken within one hour before dose)?
  3. Is dose correct for weight & renal function?
  4. Are doses being held/have recent doses been given on time?
  5. An increase in dose is likely to be needed - discuss with Microbiology or Pharmacy.
  6. If a dose increase is recommended, re-check level pre 4 th dose at new regimen.

< 15mg/L

Low

  1. Is vancomycin still needed?
  2. Is it a true pre-dose trough level (taken within one hour before dose)?
  3. Is dose correct for weight & renal function?
  4. Are doses being held/have recent doses been given on time?
  5. An increase in dose is likely to be needed - discuss with Microbiology or Pharmacy.
  6. If a dose increase is recommended, re-check level pre 4 th dose at new regimen.

10 to 15 Target Range

  1. Is vancomycin still needed?
  2. Is patient responding clinically?
  3. Continue same dose.
  4. Check level in 3 days.

15 to 20 Target Range

  1. Is vancomycin still needed?
  2. Is patient responding clinically?
  3. Continue same dose.
  4. Check level in 3 days.

>15mg/L

High

  1. Is vancomycin still needed?
  2. Is it a true pre-dose trough level (taken within one hour before dose)?
  3. Where was sample taken from? (falsely high levels can occur if taken from same line used to give vancomycin).
  4. Is dose correct for weight & renal function?
  5. Is renal function stable?
  6. Dose adjustment required - discuss with Microbiology.
  7. If the patient is to continue on vancomycin at a reduced dose re-check level as advised.

>20mg/L

High

  1. Is vancomycin still needed?
  2. Is it a true pre-dose trough level (taken within one hour before dose)?
  3. Where was sample taken from? (falsely high levels can occur if taken from same line used to give vancomycin).
  4. Is dose correct for weight & renal function?
  5. Is renal function stable?
  6. Dose adjustment required - discuss with Microbiology.
  7. If the patient is to continue on vancomycin at a reduced dose re-check level as advised.

Download / Print Section as PDF

Gentamicin Dosing & Monitoring

Gentamicin Dosing & Monitoring​

1. Overview

  • Effective gentamicin use is complex ; discuss with Microbiology or Pharmacy as required .
  • Refer to:

Table 1 – Once daily Gentamicin Dosing Guidelines

Table 2 – Administration & Monitoring Guidelines

Table 3 – Interpretation of Levels

Table 4 – Gentamicin Dosing in Infective Endocarditis ONLY

2. Patient Selection and Review

  • Avoid aminoglycosides in patients with renal impairment whenever possible. However, in cases of septic shock, a one-off full dose of gentamicin may be necessary regardless of renal function. If gentamicin is required, consult Microbiology for guidance.
  • Special populations that require Microbiology advice include:
    • Patients with CrCl <30 mL/min
    • Patients with infective endocarditis
  • Treatment should be reviewed within 24 hours and daily thereafter by consultant or registrar.
  • Treatment courses should not usually exceed 3 days .

3. Toxicity Considerations

  • Gentamicin is potentially nephrotoxic and ototoxic .
  • Monitor gentamicin levels and renal function closely .
  • Avoid prolonged treatment and co-administration with other nephrotoxins (e.g., diuretics, NSAIDs, vancomycin) where possible.
  • Note: Ototoxicity may present initially as vestibular symptoms (vertigo, ataxia) even if levels are in range.

4. Dosing and Monitoring

  • Once daily dosing is recommended for most patients (discuss dosing with Microbiology in patients with CrCl <30ml/min or endocarditis as this may vary).
    • In a patient less than 65 years with good renal function (creatinine clearance > 80ml/minute) and with good urine output do NOT hold dose while waiting for level to be reported.
  • In a patient over 65 years, or with abnormal renal function (creatinine clearance < 80ml/minute), it is generally preferable to await the result of the first gentamicin level before giving the next dose.

5. Responsibility for Monitoring

  • The clinical team must check gentamicin levels regularly and adjust dosing accordingly.
  • The laboratory does NOT notify teams about out-of-range levels.
  • Gentamicin levels are available daily from 8am to 8pm .

Table 1: Once Daily Gentamicin Dosing Guidelines

Use the Gentamicin calculator or follow the steps below to calculate Once Daily Gentamicin dose. Please ensure it is prescribed in the correct section of the LUH MPAR/Kardex (page 3).

Do NOT use the steps below to calculate dosing for patients with infective endocarditis, as an alternative dosing regimen is required. Please discuss with microbiology.

Step 1

Cautions – Consider discussing with Microbiology if any apply

  • Age ≥65
  • Renal impairment, especially severe renal impairment (CrCl <30ml/min)
  • Obesity ( use adjusted dosing weight )
  • Concurrent nephrotoxins
  • Endocarditis

Step 2

Calculate Ideal Body Weight (IBW)

Male : 50kg + (2.3 x inches over 5 feet) OR 50kg + (0.9 x cm over 152cm)

Female : 45.5kg + (2.3 x inches over 5 feet) OR 45.5kg + (0.9 x cm over 152cm)

Step 3

Calculate Dosing Weight

  • If obese (i.e. actual body weight exceeds IBW by ≥20%), use Adjusted Dosing Weight:

Adjusted Dosing Weight (kg) = Ideal Body Weight + 0.4 x (Actual Body Weight – Ideal Body Weight)

  • Non-obese patient: Use actual body weight.

Step 4

Calculate Renal Function

  • Use the Creatinine Clearance (CrCl) calculated by Cockcroft-Gault formula ( not eGFR). MDCalc or equivalent can support with calculating or equation below:

_(140 – age) x (IBW* in kg) x N_

Serum creatinine (micromol/L)

N = 1.23 males & 1.04 females

*If actual body weight < IBW, use actual body weight in this equation

Note : Neither creatinine clearance nor eGFR provide a perfect marker of renal function, particularly if rapidly changing renal function.

Step 5

Select a dose based on renal function and weight

  • If obese use Adjusted Dosing Weight (See Step 3)
  • If non-obese use Actual Body Weight

CrCl (ml/min)

Dose: round to nearest multiple of 40mg

Maximum Gentamicin in 24hours = 480mg

Dose

Frequency

Greater than 80

5mg per kg IV (up to a max of 480mg)

every 24 hours

60 to 79

4mg per kg IV

every 24 hours

40 to 59

3.5mg per kg IV

every 24 hours

30 to 39

2.5mg per kg IV

every 24 hours

less than 30

Avoid if possible.

If essential, give 2mg per kg IV (up to a max of 160mg), one dose only

Check level at 24 hours, discuss need for second dose with Micro

Intermittent haemodialysis: See Haemodialysis Dosing Guidelines

Table 2: Once Daily Gentamicin Administration & Monitoring Guidelines

Administration

Monitoring

  • Measure pre-dose (trough) levels only, ideally just before the 2 nd dose.
  • Take sample within the hour before dose is due.
  • Document on request form: date and time sample taken and date and time of last dose.
  • If the level is less than 1mg/L, re-check pre-dose levels twice per week thereafter, or more often if impaired or rapidly changing renal function, haemodynamically unstable, elderly, or on diuretic therapy.
  • Note that monitoring of renal function and clinical signs of toxicity in addition to monitoring of levels is important as toxicity may occur in patients in whom the gentamicin levels have never exceeded the acceptable range.
    • With respect to ototoxicity, vestibular disturbance (vertigo, ataxia) often precedes disturbance of hearing and should not be discounted because the patient has levels within the acceptable range.

Table 3: Interpretation of Pre-dose Levels for Once Daily Gentamicin

Target pre-dose (trough) level is <1mg/L

Level

Advice

<1mg/L

Review if gentamicin is still indicated. If yes, and renal function stable, give next dose as prescribed. If yes, but renal function abnormal or deteriorating, consider full clinical picture and use the gentamicin calculator again to re-calculate dose if needed.

≥1mg/L

1. Is gentamicin still needed?

2. Is it a true pre-dose trough level (taken within one hour before dose)?

3. Where was sample taken from (falsely high levels can occur if taken from same line used to give gentamicin)?

4. Is dose correct for weight & renal function?

5. Is renal function stable?

6. Dose adjustment required - contact Microbiology or Pharmacy to discuss on a case-by-case basis.

Table 4: Daily Low Dose Gentamicin Guidelines - for Treatment of Endocarditis ONLY

Discussion with Microbiology recommended

Dose (CrCl >80ml/min)

Dose – renal impairment

Recommended range for levels

Timing and frequency of levels

3mg/kg (maximum 240mg) every 24 hours depending on renal function and age

Contact Microbiology for advice

Pre-dose:

<1mg/L

Post-dose (peak, 1hr after dose):

10 to 12 mg/L

· Take first pre-dose (trough) level within one hour before 2 nd dose

· Take first post-dose (peak) level one hour after 2 nd dose

· Repeat pre-dose (trough) level every 3 days or more often if high risk of accumulation

· Post-dose (peak) levels need only be taken once weekly

· Adjust dose according to levels

· Monitor renal function

· Contact Microbiology/AMS Pharmacist for further advice

Other than for endocarditis and synergy, low dose gentamicin is rarely indicated. If being considered discuss with Microbiology. Once the causative organism has been identified in infective endocarditis, an alternative gentamicin dosing regimen may be indicated on consultation with Microbiology.

Download / Print Section as PDF

References

References

1. The Renal Drug Database www.renaldrugdatabase.com

2. The Sanford Guide to Antimicrobial Therapy Digital Update Feb 2018

3. Rybak et al Vancomycin Therapeutic Guidelines: A Summary of Consensus Recommendations from IDSA/ASHP/SIDP Clin Infect Dis 2009 49;325-327.

4. Thomson et al Development and evaluation of vancomycin dosage guidelines designed to achieve new target concentrations JAC 2009;63:1050-1057.