PHARMACOKINETIC STUDY OF AN ORAL CEPHALOSPORIN, CEFDINIR, IN HEMODIALYSIS-PATIENTS

The pharmacokinetics of cefdinir mere investigated in six hemodialysis patients. For the present study, two tests were carried out, one with 4 h of hemodialysis and the other without hemodialysis. Cefdinir was given orally to each patient in a dose of 100 mg, and blood was collec ted serially for 48 h after dosing in the test without dialysis and fo r 72 h in the test with dialysis. In the test without dialysis, the ma ximum plasma concentration (C-max) was 2.36 +/- 0.53 mu g/ml (mean +/- standard deviation) anal the time to C-max was 9.00 +/- 2.45 h, The t erminal elimination half-life (t(1/2)) and area under the concentratio n-time curve (AUC) were 16.95 +/- 1.20 h and 69.05 +/- 14.84 mu g . h/ ml, respectively, In the test with dialysis, t(1/2) during hemodialysi s decreased approximately to one-sixth of that obtained in the test wi thout dialysis, although t(1/2) in the latter elimination phase did no t differ from that in the nondialysis test. AUC was reduced to 43% of that in the test without dialysis. The fractional removal of cefdinir by hemodialysis was 61%, These findings indicate that clearance of cef dinir is prolonged in patients with renal failure, and cefdinir is wel l removed by introduction of hemodialysis, although t(1/2) (during hem odialysis) and AUC mere two and eight times higher than the data previ ously reported for healthy volunteers, respectively. The pharmacokinet ic data suggest that 100 mg of oral cefdinir once a day would result i n a sufficient concentration in plasma in hemodialysis patients, but t his remains to be confirmed by multiple-dose studies.