Furosemide disposition in patients on CAPD

Area of Science:

• Pharmacokinetics
• Nephrology
• Internal Medicine

Background:

• Furosemide is a diuretic commonly used in patients with fluid overload.
• Patients with renal failure, particularly those on continuous ambulatory peritoneal dialysis (CAPD), may have altered drug pharmacokinetics.
• Understanding furosemide disposition in CAPD patients is crucial for effective management.

Purpose of the Study:

• To compare the pharmacokinetics of single oral and intravenous doses of furosemide in healthy volunteers and CAPD patients.
• To investigate the impact of renal failure on furosemide absorption, elimination, and clearance.

Main Methods:

• Single oral and intravenous doses of furosemide were administered to 8 healthy male volunteers and 11 CAPD patients.
• Urinary recovery, time to maximum concentration (tmax), bioavailability, elimination half-life, and total body clearance were measured.
• Statistical analysis included calculation of 95% confidence intervals.

Main Results:

• Furosemide absorption was variable in both groups, with trends suggesting differences between volunteers and CAPD patients.
• While not statistically significant, bioavailability appeared more complete in CAPD patients (70.1% vs 53.6%).
• Elimination half-life was significantly longer (oral: 228 vs 65.1 min; IV: 195 vs 60.3 min) and total body clearance was lower (61.9 vs 138 ml/min) in CAPD patients, with negligible renal clearance.

Conclusions:

• Significant differences in furosemide disposition were observed in CAPD patients compared to healthy volunteers.
• These pharmacokinetic alterations in CAPD patients are primarily attributed to renal failure.
• Further research may be needed to optimize furosemide dosing in this population.