Treatment of a patient with end-stage renal disease with Rituximab: Pharmacokinetic evaluation suggests Rituximab is not eliminated by hemodialysis

The purpose of this study was to determine if therapeutic levels of Rituximab could be achieved in a patient with renal failure being dialyzed and if Rituximab is removed by hemodialysis. A 54-year-old man with low-grade lymphoma and renal failure on hemodialysis received 8 weekly treatments of Rituximab at 375 mg/M². Serum Rituximab levels were obtained before and after each treatment, before and after dialysis following each treatment, as well as in the dialysate fluid. The serum levels of Rituximab increased gradually with each treatment and were comparable to levels in patients with normal renal function. The postdialysis levels were higher than the predialysis levels as a consequence of hemo-concentration after dialysis. Rituximab was not detected in the dialysate fluid. The patient developed life-threatening hyperkalemia after the fourth treatment, which we believe occurred secondary to tumor lysis. Therapeutic levels of Rituximab may be maintained in patients undergoing dialysis. Rituximab is not eliminated by hemodialysis.