Pharmacokinetics of oral cephradine in continuous ambulatory peritoneal dialysis patients

Parenteral cephalosporins are widely used to treat peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD). Few data exist on oral antibiotics in treating this disease. This study examined the pharmacokinetics of oral cephradine in noninfected patients on CAPD. Assays for cephradine in dialysate and urine were performed by high-performance liquid chromatography. Following a 500-mg dose, the peak dialysate cephradine concentration was 8.7 +/- 1.4 micrograms/ml. The peak urinary concentration was 201 +/- 119 micrograms/ml. The maximum peritoneal clearance was 4.3 +/- 0.3 ml/min/1.73 m2. Dialysate cephradine concentrations were inadequate against Staphylococcus epidermidis and most gram-negative bacteria found in CAPD-associated peritonitis, but may be adequate for most strains of other gram-positive organisms causing this disease.