Evaluation of four once-daily aminoglycoside dosing nomograms

Allison Wood Wallace, Matthew Jones, Joseph S Bertino
Pharmacotherapy 2002, 22 (9): 1077-83

STUDY OBJECTIVE: To evaluate the accuracy of four once-daily aminoglycoside dosing nomograms in producing the desired gentamicin peak concentration (Cmax) target of 20 microg/ml in patients with varying degrees of renal function.

DESIGN: Retrospective analysis using prospectively collected pharmacokinetic data.

SETTING: Rural teaching hospital.

PATIENTS: Ninety patients receiving intravenous gentamicin divided into three groups (30 patients each) determined by estimated renal function: group 1, creatinine clearance (Cl(cr),) 60 ml/minute or greater; group 2, Cl(cr) 40-59 ml/minute; group 3, Cl(cr) 20-39 ml/minute. Intervention. Serum gentamicin concentrations were collected for a 2-point (two consecutive infusions and one predose and one postdose concentration sampled during steady state) or 3-point (single infusion and one predose and two postdose concentrations at least 1.5 estimated half-lives apart) pharmacokinetic study for determination of patient-specific pharmacokinetic parameters (elimination rate constant, volume of distribution at steady state, and clearance) after 30-minute infusions of gentamicin 2.8 +/- 1.6 mg/kg.

MEASUREMENTS AND RESULTS: The four nomograms evaluated were from Hartford Hospital, Barnes-Jewish Hospital, University of Rochester, and the Sanford Guide. With a pharmacokinetic analysis program and the patient-specific pharmacokinetic parameters, Cmax and minimum concentration (Cmin) were determined with use of the recommended doses and dosing intervals of the four nomograms. Also, the gentamicin dose and interval needed to achieve a Cmax and Cmin of 20 microg/ml and 0.2 microg/ml, respectively, were determined. Dosing was based on total body weight unless that weight was more than 25% of ideal body weight, in which case, an adjusted body weight was used. In general, the recommended dosages and resultant Cmax produced by the nomograms were significantly less (p < 0.05) than the dosage and Cmax actually needed to achieve a Cmax:minimum inhibitory concentration (MIC) ratio of 10 or greater for bacteria with an MIC of 2 microg/ml.

CONCLUSION: Once-daily aminoglycoside dosing using the four nomograms resulted in inaccurate dosing, and because of the large variability in human pharmacokinetics, dosing nomograms such as these should be abandoned in favor of individualizing dosages with therapeutic drug monitoring.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"