Gentamicin pharmacokinetics during slow daily home hemodialysis

Gentamicin pharmacokinetics during slow daily home hemodialysis. Gentamicin is commonly used in hemodialysis patients. Gentamicin pharmacokinetics during traditional hemodialysis have been described. Slow daily home (SDH) hemodialysis (7 to 9 hours a day/6 days a week) use is increasing due to benefits observed with increased hemodialysis. We determined gentamicin pharmacokinetics for SDH hemodialysis patients. Eight patients (four male and four female) received a single intravenous dose of 0.6 mg/kg gentamicin post-hemodialysis. Blood samples were collected at 5, 10, 15, 30, and 60 minutes after dose. The next day patients underwent a typical SDH hemodialysis (high-flux F50NR dialyzer) session. Blood samples were taken at 0, 5, 15, 60, 120, 240, 360, 480 minutes during and 15, 30 and 60 minutes post-hemodialysis. Baseline and 24-hour urine samples were collected. Pharmacokinetic parameters were calculated assuming a one-compartment model. Patients were 42.5 ± 13.1 years old (mean ± SD). Inter-, intra-, and post-hemodialysis collection periods were 17.0 ± 2.1 hours, 8.1 ± 0.4 hours, and 1.1 ± 0.1 hours, respectively. Intra-, and interdialytic gentamicin half-lives were different (intradialytic, 3.7 ± 0.8 hours; interdialytic, 20.4 ± 4.7 hours; P < 0.0001). Hemodialysis clearance accounted for 70.5% gentamicin total clearance. Renal clearance correlated with glomerular filtration rate (GFR) (renal clearance = 1.2 GFR; r2 = 0.98; P < 0.001). Mean peak and trough of hemodialysis concentrations were 1.8 ± 0.6 μg/mL and 0.5 ± 0.2 μg/mL, respectively. Post-hemodialysis rebound was 3.1 ± 8.8% at 1 hour. Pharmacokinetic model predicts 2.0 to 2.5 mg/kg dose gentamicin post-hemodialysis would provide peak (1 hour post-dose) and trough (end of SDH hemodialysis session) concentrations of 6.0 to 7.5 μg/mL and 0.7 to 0.8 μg/mL, respectively. This would provide adequate coverage for most gram-negative organisms in SDH hemodialysis patients.