Gentamicin clearance during hemodialysis: a comparison of high-efficiency cuprammonium rayon and conventional cellulose ester hemodialyzers.
The advent of high-efficiency hemodialyzers has afforded improved efficiency of urea clearance; however, increased clearance of other substances, particularly antibiotics, also may occur, necessitating changes in clinical practice. Accordingly, we compared the efficiency of gentamicin removal using two different hemodialyzers, a conventional saponified cellulose ester (CD 135) and a high-efficiency cuprammonium rayon dialyzer (TAF 175L), in eight hospitalized patients undergoing antibiotic therapy for suspected or proven gram-negative infection. The rate of dialysis, estimated as the ratio of dialyzer urea clearance (K) to urea distribution volume (V) (K/V urea), and the total elimination rate constant (k) of gentamicin were measured during 17 hemodialysis treatments. The K/V urea for the two dialyzers, TAF 175L and CD 135, was 0.390 +/- 0.024 hr-1 and 0.413 +/- 0.129 hr-1 (P = NS), respectively. The TAF 175L hemodialyzer was almost twice as efficient in removing gentamicin as the CD 135: TAF 175, k = 0.263 +/- 0.024 hr-1; CD 135, k = 0.132 +/- 0.027 hr-1 (P < 0.001). Moreover, the rate of dialysis (K/V urea) was correlated with k of gentamicin for the TAF 175L dialyzer (r2 = 0.50, P < 0.02) but not for the CD 135 dialyzer. We conclude that dialyzer characteristics and the rate of dialysis (K/V urea) should be taken into consideration when determining the dosage of gentamicin in patients on hemodialysis.
Agarwal
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Department of Internal Medicine, University of Texas, Southwestern Medical Center, Dallas 75235-8856.
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D000328:Adult; D000368:Aged; D002482:Cellulose / Q000031:analogs & derivatives*; D005260:Female; D005839:Gentamicins / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D012044:Regression Analysis; D006435:Renal Dialysis / Q000295:instrumentation*
D005839:Gentamicins; D008567:Membranes, Artificial; C066013:AM 160H; D002482:Cellulose