Once versus individualized multiple daily dosing of aminoglycosides in critically ill patients

The purpose of this study was to evaluate the once daily dosing (ODD) program in critically ill Egyptian patients compared to individualized multiple daily dosing (MDD) in terms of clinical and bacteriological efficacy. In addition, the incidence of nephrotoxicity associated with both regimens in this specific group of patients was assessed.

Fifty-two patients with suspected or confirmed bacterial infections admitted to the Critical Care Medicine Department, Kasr El-Aini-Cairo University Hospitals comprised the study population. The amikacin group (30 patients) was sub-divided into 14 patients receiving amikacin ODD (1 g i.v.) and 16 patients receiving amikacin in MDD (500 mg i.v./dose). The gentamicin group (22 patients) was sub-divided into 10 patients receiving the drug ODD (240 mg i.v.) and 12 patients receiving gentamicin MDD (80 mg i.v./dose). Amikacin or gentamicin serum levels were determined by the enzyme multiplied immunoassay technique using Emit 2000. MDD regimen was adjusted based on the individual pharmacokinetic parameters using the Sawchuk-Zaske method.

There was no significant difference between the two dosing regimens with regard to clinical and antibacterial efficacy or incidence of nephrotoxicity of both gentamicin and amikacin groups. In the ODD regimen, duration of treatment had no effect on increasing incidence of nephrotoxicity unlike the individualized MDD regimen. No dose adjustments were needed in the once daily dosing regimen since trough concentrations have never been above toxic level.

The study showed that the ODD regimen is preferred in critically ill patients to individualized MDD as shown by comparable efficacy, nephrotoxicity and lesser need for therapeutic drug monitoring and frequent dose adjustments required in the individualized MDD regimen.