Post hoc analysis of the SONAR trial: potential analgesic effects of atrasentan?

Chan et al. conducted a post hoc analysis of the Study of Diabetic Nephropathy with Atrasentan (SONAR) to demonstrate that atrasentan reduced chronic pain-related adverse events reported by investigators and the initiation of analgesics. This study creates an interesting hypothesis, but it is limited in that the pain information was collected as part of the adverse events and the presence/absence of pain at baseline was unknown. Thus, prospective clinical trials are required to confirm these findings.