Dosing Once daily Gentamicin |
1 | Determine weight of patient. Use Ideal rather than Actual body weight if patient has a BMI > 30 as Gentamicin does not distribute in adipose tissue. Courses should not go beyond 7 days without senior microbiological advice |
2 | Determine creatinine clearance = (140-age) x weight in kg x 1.29 in men or x 1.04 in women |
3 |
Creatinine clearance > 30 ml/min: Dose 5 mg/min. Max dose/day 480 mg
Creatinine clearance < 30 ml/min: Dose 3 mg/min. Max dose/day 320 mg
Doses should be rounded down to the nearest 40 mg
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4 | Measure trough level at 24 hours after first dose. In patients <65 years old, with good urine output give and normal renal function then 2nd dose may be given once trough level done but without waiting for result. Otherwise check and wait for trough result. The pre-dose trough gentamicin level must be less than or equal to 1mg/L before a further dose is given. If the level is elevated and timing and sampling are correct, levels will need to be repeated at 12–24 hours depending on the original result. It may be necessary to increase the dosing interval to 36-48 hrs. If Gentamicin is re-started, recheck levels before the next dose.
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5 | Do not prescribe >24 hours in advance. There have been multiple clinical incidents where the patient has been prescribed 48 hourly gentamicin, which has subsequently been administered 24 hourly due to prescribing a day in advance. |
6 | Give the recommended dose by infusion in 100ml sodium chloride 0.9% over 30 minutes. |