Clinical application of amikacin dosage based upon lean body mass in patients with different renal function

To determine an adequate dosage of amikacin, a pharmacokinetic model was used based on lean body mass (LBM), age and serum creatinine. Amikacin was administered during a mean period of 7 days to patients with normal (group I, n = 15, CCr greater than 60 ml/min), impaired stable (serum creatinine within a range of 50 mumol/l), (group II, n = 10) and unstable (group III, n = 8) renal function. The mean trough and peak blood levels were less than 2 and 24, 4.5 and 25 and 7 and 26 micrograms/ml in groups I, II and III, respectively. In group II and III a maximum trough level of 10 instead of 5 micrograms/ml was permitted to prevent a prolonged period of low subtherapeutic levels. With this modification the regimen in both groups appeared satisfactory. The pharmacokinetic model allows an accurate dosage regimen in all groups and can easily be programmed into a pocket calculator.