Doses of antibiotic in patients with renal insufficiency

The pharmacokinetic properties of cefotaxime were studied in 30 subjects with various degrees of renal function after a single 1-gm intramuscular injection. Serum and urinary concentrations of cefotaxime and desacetyl cefotaxime were determined by high-pressure liquid chromatography. The pharmacokinetic parameters were obtained using a one-compartment open model. A significant (P less than 0.0001) linear correlation was demonstrated between the elimination rate constant of cefotaxime and creatinine clearance. The mean serum half-life of cefotaxime was 0.86 hour in normal subjects and was prolonged to 2.35 hours in hemodialysis patients. The mean 24-hour urinary recovery was 51.7% as cefotaxime and 25.6% as desacetyl cefotaxime in normal subjects. In the present study, modification of the dosage is probably unnecessary in patients with creatinine clearance of more than 30 ml/min; however, dose reduction or prolongation of dosage interval, or both, may be appropriate in patients with severe renal dysfunction.