Hemodialysis clearance of theophylline

The serum hemodialysis clearance of theophylline was determined in 4 patients compared to systemic serum clearance off dialysis in 3 patients. The serum extraction ratio values obtained were compared to those of urea. Hemodialysis clearance of theophylline averaged 84.3 +/- 11.6 ml/min (mean +/- SD), and extraction ratios obtained were found to be a fairly consistent fraction of the urea extraction ratio (0.72 +/- 0.08). Hemodialysis clearance increased total body clearance (ClTB) off dialysis by 130%, 387%, and 176% in the patients who had their theophylline serum clearance estimated off dialysis. Difference in reported hemodialysis clearance are probably related to the type of dialyser used. Studies utilizing hollow fiber systems (the present study) consistently yielded higher theophylline dialysis clearance values than those using coil systems (84.3% to 88.1 ml/min versus 32 to 39.4 ml/min). Patients receiving theophylline on hemodialysis should be closely monitored for bronchospasm during and after the hemodialysis procedure. Measurement of serum concentrations should be employed to facilitate dosage increases during hemodialysis.