Individual patient risk assessment and cost–benefit analysis of patiromer in AMBER – Authors' reply

[...]we do not believe that O'Sullivan and MacIntyre's description of the left side of the U-shaped curve is relevant to the findings of our study. The change in systolic blood pressure from baseline to 12 weeks was a secondary endpoint in AMBER.1 We have proposed that our finding of unanticipatedly long half-lives of biologically active spironolactone metabolites in patients with chronic kidney disease explains why blood pressure remained lower in the placebo group for several weeks after discontinuation of spironolactone.2 But we do agree with O'Sullivan and MacIntyre that systolic blood pressure is a clinically relevant endpoint, and a longer study would have been more desirable to show differences in blood pressure; however, enabling the safer use of spironolactone was the necessary first step towards designing an outcomes trial. RA reports personal fees from AbbVie, Akebia, Amgen, AstraZeneca, Bayer, Birdrock Bio, Boehringer Ingelheim, Celgene, Daiichi Sankyo, Eli Lilly, Gilead, GlaxoSmithKline, Ironwood Pharmaceuticals, Johnson & Johnson, Merck, Novartis, Opko, Otsuka, Reata, Relypsa, Sandoz, Sanofi, Takeda, and ZS Pharma, unrelated to this Correspondence; has served as associate editor of the American Journal of Nephrology, Nephrology Dialysis and Transplantation, is an author of UpToDate; and has received research grants from the US Veterans Administration and the National Institutes of Health.