Tobramycin kinetics during continuous ambulatory peritoneal dialysis.
To establish therapeutic guidelines for tobramycin use in patients receiving continuous ambulatory peritoneal dialysis (CAPD), we studied tobramycin single-dose kinetics in CAPD patients. Tobramycin was studied after a 1.5-mg/kg dose given either intravenously (TOB-IV) or intraperitoneally (TOB-IP). TOB-IV provided a plasma concentration above 3 mg/l at 12 hr with a t 1/2 of 39.5 hr. When tobramycin was given intraperitoneally, 52% of the dose was absorbed; peak plasma concentrations were only 1.8 mg/l, and the t 1/2 was 35 hr. CAPD accounted for only 15% to 20% of total body clearance in both groups. The kinetic principle of superposition was used to predict plasma concentrations after repeated TOB-IP. A model using once-a-day dosing predicted that a loading dose of 4 mg/kg followed by 1.5 mg/kg would achieve steady-state plasma concentrations of 2.8 to 4.2 mg/l. Another model using tobramycin in each exchange predicted that a loading dose of 3 mg/kg followed by 0.3 mg/kg would provide steady-state plasma concentrations of 2.8 to 3.1 mg/l. These data should be useful in treating CAPD patients with tobramycin who have nonperitoneal gram-negative aerobic bacterial infections, as well as those who require the drug for peritonitis.
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D006801:Humans; D007263:Infusions, Parenteral; D007274:Injections, Intraperitoneal; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D007700:Kinetics; D008875:Middle Aged; D008954:Models, Biological; D010530:Peritoneal Dialysis; D010531:Peritoneal Dialysis, Continuous Ambulatory; D014031:Tobramycin / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D014031:Tobramycin