SPLogo2mic.gif (9925 bytes)

        SydPath

 internet.gif (1322 bytes)

Aminoglycoside Prescribing

Return to SydPath Internet Homepage
Return to Information Sheet Page
 

 

 

A. Patients with Creatinine Clearance > 1.2 mL/s (normal renal function)
B. Patients with Creatinine Clearance < 1.2 mL/s (reduced renal function)

Aminoglycoside nomogram
Creatinine Clearance Estimation         (On-line Calculator)
Lean Body Mass Estimation               (On-line calculator)
Contact Numbers

A. PATIENTS WITH CREATININE CLEARANCE >1.2mL/sec

1. Recommended daily dose of gentamicin, tobramycin or netilmicin is 5mg/kg (lean body mass).

Doses of 6 or 7 mg/kg may be prescribed for immediately life threatening infections after seeking specialist advice.

Note: Twice daily dosing is still recommended for infective endocarditis and may be more appropriate for patients with significant burns or ascites. Relative contraindications to aminoglycoside use: pregnancy, ascites.

2. Give as a single IV dose over 30 minutes

3. Monitoring

• Levels should be measured between 6 and 14 hours after the first dose or after any change in dose.

  • plot the plasma concentration on the aminoglycoside nomogram
  • if the level fails between the minimum and maximum lines continue with the same dose
  • if the level is above the maximum line, the dose should be decreased
  • if the level is below the minimum line the dose may need to be increased

• Subsequent levels should be measured every 48 - 72 hours in patients with STABLE renal function.                                                                                        (return to top)
 

B. PATIENTS WITH CREATININE CLEARANCE <1.2mL/sec

Care should be exercised in prescribing to the elderly and in patients with pre-existing renal impairment. In patients with deteriorating renal function the routine use of an aminoglycoside is not recommended.              (return to top)

1. Loading dose
Creatinine Clearance
(mL/s)		 Starting Dose
(mg/kg Lean Body Mass)
0.7 - 1.2 5
0.5 - 0.7 4
0.3 - 0.5 3
<0.3 Seek Specialist advice

2. Order drug level

3. Give as a single IV dose over 30 minutes

4. Subsequent doses and monitoring

  • for dose prediction contact ward pharmacist then follow ward pharmacists recommendation for monitoring
  • after hours/weekends contact Senior on wards. Dosage prediction available in Emergency Department for problem cases.
  • check microbiology culture results and sensitivity tests as change to another antibiotic maybe appropriate.                   (return to top)

AMINOGLYCOSIDE NOMOGRAM

IntrFSAmgsideGIF.gif (25821 bytes)

Data based on population kinetics for 4 mg/kg (lower line) and 7 mg/kg (upper line).

Creatinine Clearance Estimation: (Cockroft & Gault)      (return to top)

Males (mL/s) = (140-age) x Lean Body Mass (kg)
                         48600 x serum creatinine (mmol/L)

Females use the same formula x 0.85

Reference Interval: 1.5 - 2.5 mL/s                                         (On-line Calculator)

Lean Body Mass:                                              (return to top)

Males (kg)  = 50 kg plus 0.9 kg for every cm of height > 150 cm
Females (kg) = 45 kg plus 0.9 kg for every cm of height > 150 cm
                                                                                    (On-line calculator)

Contact numbers                                   (return to top)

  • St Vincent's Hospital Pharmacy Department 2687 or page ward pharmacist
  • Clinical Pharmacology and Toxicology Registrar on 2044 or pager 6822
  • Microbiology Registrar 2317 or pager 6890
Updated 29/12/99 GJones