- Gentamicin, IV, 5–6 mg/kg once daily.
- If BMI is >40 kg/m2 use ideal body weight* + 40% of the difference between ideal and actual body weight.
- Administer slowly over 3 minutes or infused over 20–30 minutes up to 2 hours, diluted in 5% dextrose or 0.9% sodium chloride solution.
- For streptococcal endocarditis: 1.5 mg/kg 12 hourly (in combination with penicillin).
- Renal impairment dosage adjustment (eGFR <60 mL/minute):
- Administer 3–4 mg/kg loading dose and adjust further dosing according to plasma concentrations.
- Gentamicin is potentially nephrotoxic and ototoxic – monitor creatinine three times per week and discontinue if vestibular or cochlear symptoms develop.
- Therapeutic drug monitoring: Sample after the third dose;
- Draw trough concentrations immediately before dose; peak concentrations 0.5–1.0 hours after dosing from the drip-free arm.
- Therapeutic ranges: Peak >8 mcg/ml, trough <1 mcg/ml
- Reduce the dose per kg or consider omitting a dose if concentration is supratherapeutic. If the plasma concentration is subtherapeutic but the patient has signs of toxicity, change to an alternative agent.
* ideal body weight calculator: https://www.mdcalc.com/ideal-body-weight-adjusted-body-weight