[Pharmacologic studies or aminoglycoside antibiotics (amikacin, gentamicin, sisomicin, tobramycin)]

In a randomized study of 12 healthy subjects, the pharmacokinetics of gentamicin, sisomicin and tobramycin were determined after a one-hour infusion of each drug (1.0 mg/kg body-weight). There were no pharmacokinetic differences of therapeutic significance between the three drugs. The mean serum concentrations at the end of infusion were 3.85 microgram/ml for gentamicin and 4.66 microgram/ml for sisomicin, falling to 0.12 and 0.26 microgram/ml, respectively, after eight hours. The biological half-life varied between 96 and 122 min and the apparent volumes of distribution corresponded closely to the size of the extracellular space.--The pharmacokinetic data of amikacin were determined after a one-hour constant infusion, the mean amikacin serum concentration was 37.5 microgram/ml and, 8 hours later, decreased to an average of 1.3 microgram/ml. The biological half-life amounted to a mean of 114.2 +/- 16.7 min, and the apparent volume of distribution could be calculated with 18.1 +/- 1.81/100 kg body weight.