Comparison of pharmacological and antimicrobial properties of cefadroxil and cephalexin.

Pharmacological and antimicrobial properties of cefadroxil, a new cephalosporin antibiotic, were compared with cephalexin. Absorption and excretion were studied in 20 healthy men. Peak concentrations of the drugs in serum were similar after ingestion of single 500-mg tablets. The concentration of cefadroxil in serum was more sustained than that of cephalexin. Levels of cefadroxil in serum after a dose of 1,000 mg were approximately twice those after a 500-mg dose through 6 h. Each drug administered in a dose of 500 mg every 6 h for 24 h resulted in concentrations in serum that were similar to a single dose without accumulation. Ninety-three percent of the cefadroxil and 85% of the cephalexin were excreted in urine after ingestions of single 500-mg tablets. The urine concentration of cefadroxil was more sustained than cephalexin. Minimal inhibitory and minimal bactericidal concentrations for clinical isolates were comparable with each drug. Cefadroxil compares favorably with cephalexin in this study. Sustained levels of cefadroxil in serum and urine suggest that this drug may be given at less frequent intervals than cephalexin.