Pharmacokinetic evaluation of single daily dose amikacin

The pharmacokinetic parameters of amikacin given once daily were compared to those of amikacin given bd at different daily dosages. In adult patients, 'peak' serum concentrations (30 min after 30 min infusion) were linearly proportional to the dose given with the following equation:-'peak' = 4.23 (dose in mg/kg)-3.93 (r, 0.827; P less than 0.0001). Areas under curves were also proportional to the dose and were not affected by the schedule of administration (od or bd). Serum half-life was neither affected by the dose nor the schedule of administration. However, the half-life was approximately 3 h in adult patients with infections and was greater than 4 h in elderly patients. In multiple dose studies, no accumulation was observed either in children or adults. However, 'peak' serum concentrations increased slightly. New recommendations for therapeutic drug monitoring need to be formulated.