Comparison of Pharmacological and Antimicrobial Properties of Cefadroxil and Cephalexin

Abstract

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.

Comparative Pharmacokinetics of Cephalexin, Cefaclor, Cefadroxil, and CGP 9000

“…In experimental infections in animals, CGP 9000 proved to be superior to cephalexin (27). The bioavailability of cephadroxil administered orally is superior to that of cephalexin (10,22). In the present study, the pharnacokinetic parameters of these three new substances and cephalexin were compared after oral administration to each of 12 fasting subjects.…”

Pharmacokinetics of Cefadroxil in Normal Subjects and in Patients with Renal Insufficiency

“…The area under the serum concentration versus time curve is larger and bioavailability greater for cefadroxil [1,7], Our pharmacokinetic results are consis tent with those noted by other authors [5] who also found a peak serum level of 25-26/ig ml"1 at 1.59 h and elimination halflife of 1.51 h after ingestion of 1,000 mg of cefadroxil. The average elimination se rum half-life was 1.39 h and thus longer than that of cephalexin (0.9-1.1 h) [4,7] and two times longer than that of cephradine (0.6-0.7 h) [7], Like in other cephalospo rins, urinary elimination was very high, since 93.0% of the dose was recovered in the urine during the first 24 h; urinary con centrations of the antibiotic were conse quently very high. In patients with chronic renal insufficiency, the peak serum level of cefadroxil increased as soon as renal func tion decreased (p < 0.001).…”

Pharmacokinetics of β-Lactam Antibiotics

“…As suggested earlier, cephalexin is well absorbed following a wide range (0.125-2.0 g) of oral doses administered as capsule, tablet, solution, or suspension (THORNHILL et al 1969;GOWER and DASH 1969;BERGAN et al 1970;GRIFFITH and BLACK 1971;O'CALLAGHAN et al 1971;LoDE et al 1979;BARRIOS et al 1975;Ac-TOR et al 1976a;PFEFFER et al 1977;HARTSTEIN et al 1977;HENNESS et al 1978;FINKELSTEIN et al 1978;CHOW et al 1979;BUSTRACK et al 1980;SIMON 1980 a;LE-CAILLON et al 1980;LODE et al 1980c). Peak serum concentrations of cephalexin occur within 1-2 h, dependent upon the formulation.…”

“…Thirty-eight percent to 58% of the dose was excreted unchanged in urine in 3 hand 85%-93% was recovered in 24 h. Regimens of 500-1,000 mg every 6 h did not lead to drug accumulation in serum, whereas 1,500 mg every 6 h led to a small amount of accumulation. The apparent serum half-life of cefadroxil appears to be approximately 1-1.5 h. Administration with food does not affect the plasma levels or urinary recovery ofcefadroxil (HARTSTEIN et al 1977;PFEFFER et al 1977;JOLLyet al 1977;HENNESS et al 1978;LoDE et al 1980c;SIMON 1980a;PRENNA and RIPA 1980). BUCK and PRICE (1977) determined the serum protein binding of cefadroxil to be 20% by ultrafiltration over a drug concentration range of 10-25 ~g/ml.…”