Hemodialysis of Theophylline in Uremic Patients

Abstract

Hemodialysis of theophylline was studied in 3 uremic patients. The dialysis clearance ranged from 75.6-97.9 ml/min and averaged 88.1 ml/min. A much smaller value of 32.8 ml/min was reported by Levy and associates. The difference may be attributed to the 2 monitoring factors during hemodialysis, i.e., blood and dialyzate flow rates. Both were higher in this study. Analysis of the semilogarithmic plots of the arterial plasma concentration versus time over a 3 h period gave apparent half-lives of 3.15, 2.04 and 2.73 h, respectively, for the 3 patients. Half-life of theophylline in normal subjects ranged from 4-6 h or longer. A prolonged half-life of theophylline in uremia could be expected. An approximately 50% reduction in terminal half-life during hemodialysis was found. Hourly dialyzate was collected from one patient to account for drug recovery in the dialysis fluid. Of the administered dose, 40% was recovered in the dialyzate during a 3 h dialysis period, indicating effective removal. Dialysis clearance for creatinine was calculated by arterial-venous difference and correlated with that of theophylline. Theophylline was cleared by the dialyzer at a rate approximating 63% of creatinine removal.