[Build up of a given concentration of tobramycin and sisomycin in the blood of young children by the intravenous infusion of the antibiotics according to a calculated regimen].

Three regimens for intravenous infusion of tobramycin and sisomicin in doses of 1.33 and 1 mg/kg, respectively were analysed theoretically with the use of the constants of a two-compartmental model characterizing the tobramycin pharmacokinetics in adults. The regimen implied administration of the antibiotics by means of a 12-hour infusion. The second regimen consisted of a jet injection of the initial dose simultaneously with the beginning of the maintenance infusion. The third regimen consisted of a rapid initial infusion followed by a slow maintenance infusion. It was shown that maintenance of the drug concentration at the required levels, i.e. 2-8 microgram/ml for tobramycin and 2-61 microgram/ml for sisomicin was most safely provided by the regimen of the subsequent infusions. This regimen was tried clinically in the treatment of 17 children aged 2 months to 2.5 years with severe forms of acute pneumonia. The rate of the 25-minute initial infusion of tobramycin was 22.2 microgram/kg . min and that of the subsequent 2.7-hour maintenance infusion was 4.85 microgram/kg . min, the total dose being 1.33 mg/kg. The rate of the 20-minute initial infusion of sisomicin was 21.7 microgram/kg . min and that of the subsequent 2.4-hour maintenance infusion was 3.88 microgram/kg . min, the total dose being 1 mg/kg. It was shown that the levels of both the antibiotics in the blood serum of the patients were within the required ranges.