[Clinico-pharmacologic studies on pefloxacin].

The impact of liver impairment, renal insufficiency and age-related changes on the pharmacokinetics of pefloxacin was studied in 55 patients. The elderly patients were stratified into three age groups (61-70, 71-80 and above 81 years). The patients suffering from various infections were treated with oral or intravenous pefloxacin in a dose of 400 mg bid. Blood samples were withdrawn on the first and seventh day of therapy. The pharmacokinetics of pefloxacin was characterized by marked interindividual differences that became even more pronounced during multiple dosing. The elimination rate of pefloxacin during therapy slowed down, presumably due to its decreased metabolism. In elderly patients, the rate of cumulation is greater than in the young ones, but no significant differences could be detected among the elderly age-groups. Pefloxacin elimination also decreased in renal and hepatic impairment. There was no correlation between serum concentrations of pefloxacin and the development of adverse effects. In elderly subjects and in patients with renal or hepatic impairment, dose reduction might be considered. In mild or moderate infections or in urinary tract infections smaller doses of pefloxacin also could assure good therapeutic results. However, in severe infections especially caused by less susceptible pathogens, routine dose reduction is not recommended because of the significant interindividual differences in serum concentrations of pefloxacin.