EFFECTIVE CLEARANCE OF METHOTREXATE USING HIGH-FLUX HEMODIALYSIS MEMBRANES

We report the first series demonstrating effective clearance of methot rexate using acute intermittent hemodialysis with a high-flux dialyzer . The study was performed on six patients, two females and four males aged 13 to 72 years, All were patients at M.D. Anderson Cancer Center. Patients were dialyzed for 4 to 6 hours daily using a Fresenius F-80 membrane (Fresenius inc, Walnut Creek, CA), Following the initiation o f dialysis, there was a reduction in arterial and venous serum concent ration of methotrexate with time. Mean plasma clearance of methrotrexa te during dialysis in these six patients was 92.1 +/- 10.3 mL/min. One patient who was nearly functionally anephric was studied in detail, I n this patient, following a high dose of methotrexate (7.2 g/m(2)), ap proximately 63% of this dose was cleared with 6 hours of hemodialysis. With subsequent dialysis performed daily for 6 hours, the drug was cl eared completely in 5.6 +/- 0.3 days (n = 7 separate methotrexate trea tments), A reduction in plasma methotrexate concentration from 1,733 /- 40 mu mol/L 1 hour postinfusion to less than 0.3 mu mol/L in 5 to 6 days was observed for these seven separate treatments. We conclude th at significant clearance of methotrexate can be achieved with high-flu x dialyzers, making methotrexate therapy a viable treatment option in patients with responsive malignancies despite the presence of renal fa ilure. (C) 1996 by the National Kidney Foundation, Inc.