The influence of ascites on the pharmacokinetics of amikacin.

The pharmacokinetics of Amikacin are studied after the administration of 7.5 mg/kg body weight to 10 ascitic patients diagnosed with various hepatic disorders. The antibiotic was determined microbiologically in plasma and in the ascitic fluid. The antibiotic follows a two-compartment kinetic model, and it may be seen that once the rapid disposition phase has ended, an inflexion in the plasma-time levels curve takes place, with a passing increase in the plasma concentrations. From the pharmacokinetic study of Amikacin in these patients, it may be deduced that the ascitic liquid forms part of the central compartment for the effects of distribution, though not for the effects of elimination. The plasma half-life of the slow disposition phase is analogous to that obtained from non-ascitic patients with normal renal function. In one of the patients, the antibiotic was administered intraperitoneally; following this, the plasma concentrations of Amikacin were detected. In the last of the 10 patients included in the survey, the evolution of the plasma concentrations of the antibiotic were studied while the patient was undergoing a multiple dosage regimen with the aim of determining the accumulation of Amikacin in the ascitic fluid. A dosage regimen of multiple doses is programmed which should guarantee the efficiency and safety of the antibiotic.