Gentamicin (once daily loading dose)

Gentamicin dosing interval

• Plot the level on the nomogram. If the level falls in the area designated 24hours, 36hours or 48hours the dosing interval is 24, 36 or 48 hourly respectively.
• If the level falls on a line between dosing intervals choose the longer interval.
• If the level is above the 48 hour line STOP the treatment. If the gentamicin is to be continued take daily levels but do not give any more gentamicin until the level falls below 2mg/L.

Renal function

• U & Es and creatinine need to be checked daily in all patients on the Hartford Gentamicin Regimen.
• Repeat gentamicin levels as shown in the table.
• If the serum creatinine is rising significantly (20% or more), and it is still within 6-14 hours of the start of this gentamicin infusion measure the gentamicin level as soon as possible. If more than 14 hours contact microbiology or pharmacy for advice.

Don't use in:

• Children
• Cystic fibrosis
• Profound neutropenia
• Pregnancy
• Endocarditis
• Extensive third space fluid (e.g. ascites or oedema)

Manual dose calculation

• Calculate dose determining weight. (DDW)
• Calculate creatinine clearance. (CrCl)
   
• Age < 65 years 5 mg / kg
  Age ≥ 65 years 3 mg / kg
   
• CrCl < 10 mls/min = 2 mg / kg
  CrCl 10 - 49 mls/min = 3 mg / kg
  CrCl ≥ 50 mls/min = 5 mg / kg
   
• Round to nearest 40mg increment e.g. 320mg or 360mg
• Give as an infusion in 100 mls N-Saline over 30 minutes

Incompatibility