Single-dose pharmacokinetics of intraperitoneal ofloxacin in patients on continuous ambulatory peritoneal dialysis

The present study examines the pharmacokinetics of ofloxacin given in a single dose of 200 mg intraperitoneally (ip) in the first bag of three 2-L 8-hour exchanges. Ofloxacin was measured using high-pressure liquid chromatography (HPLC) in the serum and peritoneal effluent over 24 hours. Six patients without and 3 patients with peritonitis were studied. Ofloxacin given ip was almost completely absorbed after an 8-hour dwell, and this was not affected by peritonitis. The time required to reach peak serum concentration was longer than that reported previously following oral administration. Elimination half-life (T1/2) of ofloxacin was markedly prolonged compared to patients with normal renal function. Peritoneal clearance accounted for only one-tenth of total serum clearance. Peritonitis appeared to shorten the T1/2 of ofloxacin, but this was mainly due to an increase in total serum clearance rather than a change in peritoneal clearance. Peritoneal drug concentration > 0.5 mg/L was reached in the second and third exchange by the second hour. No side effects from ip ofloxacin were observed. We concluded that ofloxacin given in a single dose of 200 mg is safe and provides adequate therapeutic serum and peritoneal concentration for more than 24 hours in patients on continuous ambulatory peritoneal dialysis (CAPD) with 8-hour exchanges.