Pharmacokinetics of once daily intraperitoneal cefazolin in continuous ambulatory peritoneal dialysis patients

This study determined the pharmacokinetic characteristics of once daily int raperitoneal (IP) cefazolin in continuous ambulatory peritoneal dialysis (C APD) patients. Each of the 10 volunteer CAPD patients without active perito nitis received a single IP dose of 1 g of cefazolin sodium for a 6-h dwell. All patients underwent a fixed CAPD regimen comprising a first 6-h dwell f ollowed by two 3-h dwells and a final 12-h overnight dwell. Blood and dialy sate samples were collected at 0, 0.5, 1, 2, 3, 6 (end of first dwell), and 24 h after the administration of IP cefazolin. Any urine produced was coll ected over the 24-h study period. A validated HPLC method was used to analy ze cefazolin in plasma, dialysate, and urine. The bioavailability was found to be 77.9 +/- 3.1%, volume of distribution 0.20 +/- 0.05 L/kg, and plasma half-life 39.9 +/- 25.4 h. Mean total? renal, and peritoneal clearances we re 4.5 +/- 2.3, 1.4 +/- 1.1, and 3.5 +/- 1.8 ml/min, respectively. Mean pla sma and dialysate concentrations at 24 h were 42.8 +/- 14.3 and 31.8 +/- 11 .7 mcg/ml, respectively, well above the minimum inhibitory concentrations ( MIC) of susceptible organisms. A once daily IP cefazolin dose of 500 mg/L g ave desirable pharmacokinetic attributes for use as a suitable alternative to vancomycin for empiric treatment of CAPD-associated peritonitis.