Amikacin Dosing in the Intensive Care Unit

Once-daily Administration (ODA) of aminoglycosides has been a dosing strategy in use for several years.[1,2] The rationale behind ODA Administration is to optimize the pharmacodynamic properties of the aminoglycosides; more specifically, ODA results in a higher peak serum concentration than traditional multiple daily dosing can achieve, which enhances the concentration-dependent bactericidal killing activity of the compound. Additionally, aminoglycosides exhibit a postantibiotic effect which is exerted during the drug-free interval at the end of the ODA interval. During the postantibiotic effect, the organism is essentially stunned and does not replicate.[1,2]

Dosing recommendations for gentamicin/tobramycin for ODA range from 5 to 7 mg/kg, using the higher dose for select critically ill patients, and a multiple of 4 for amikacin (20-28 mg/kg, again using the higher dose for select critically ill patients).[1,3,4]

Critically ill patients have exhibited variability in pharmacokinetics that can require higher dosage requirements.[1,5] Additionally, such patients can experience rapid changes in fluid status and renal function, requiring careful monitoring of serum aminoglycoside concentrations to ensure efficacy and avoid nephrotoxicity. It is recommended to avoid trough amikacin serum concentrations of higher than 5 mcg/mL.[6]

Saludos Cordiales

Dr. José Manuel Ferrer Guerra