Renal function in amyotrophic lateral sclerosis patients on long-term treatment with edaravone

Edaravone, a free radical-scavenger, was approved in Japan for the treatment of amyotrophic lateral sclerosis (ALS). However, the effect of the drug on renal function in ALS patients remains unclear. This study aimed to investigate renal function in ALS patients on long-term treatment with edaravone by measuring the serum estimated glomerular filtration rate based on cystatin C (eGFR-CysC). In a retrospective study, the data of ALS patients who were treated with over 10 cycles of intravenous edaravone treatment and were evaluated by eGFR-CysC before and after 10 cycles of treatment between July 2015 and June 2018 were analyzed. Then, the results were compared with those of a control ALS group that had never been treated with edaravone. There were 11 patients with ALS who received over 10 cycles of intravenous edaravone treatment. The mean interval between the first and final eGFR-CysC measurements was 18.7 ± 7.9 months. Three patients (27.3%) had >20 mL/min/1.73 m(2) decrease in serum eGFR-CysC. However, no patients discontinued edaravone treatment because of renal dysfunction. The average variation rate of eGFR-CysC was not different between the long-term edaravone group (0.29 ± 1.07) and the control group (–0.34 ± 0.40). This retrospective, single-center analysis showed no clinical exacerbation of renal function in ALS patients who received long-term treatment with edaravone.