In the FIDELIO-DKD study, finerenone lowered the risk of cardiorenal consequences in patients with CKD and type 2 diabetes. In FIDELIO-DKD, researchers provided the incidences and risk factors for hyperkalemia with finerenone and placebo. The post-hoc safety study classified hyperkalemia as mild or moderate based on blood potassium values of >5.5 or >6.0 mmol/L measured at all regular visits. The Aalen–Johansen estimate was used to calculate cumulative occurrences of hyperkalemia with mortality as a competing risk. Significant independent predictors of hyperkalemia were established using a multivariate Cox proportional hazards model. Restricted cubic splines were used to examine the associations between short-term post-baseline changes in serum potassium or eGFR and the risk of hyperkalemia. Serum potassium levels dictated medicine dosage during the research. Patients in either group who had moderate hyperkalemia had their study medicine withheld until their serum potassium level reached 5.0 mmol/L, at which point the treatment was reintroduced at the 10 mg daily dose. Patients who were given a placebo received fake therapy stoppage and down titration.

Over a median follow-up of 2.6 years, 597 of 2,785 (21.4%) and 256 of 2,775 (9.2%) patients treated with finerenone and placebo, respectively, suffered treatment-emergent mild hyperkalemia; 126 of 2,802 (4.5%) and 38 of 2,796 (1.4%) patients experienced moderate hyperkalemia. Higher blood potassium, lower eGFR, greater urine albumin-creatinine ratio, younger age, female sex, -blocker usage, and finerenone assignment were independent risk factors for moderate hyperkalemia. The use of diuretics or sodium-glucose cotransporter–2 inhibitors lowered the risk. Short-term increases in serum potassium and reductions in eGFR were related with future hyperkalemia in both groups. The degree of elevated hyperkalemia risk for any change from baseline was less with finerenone than with placebo at month 4.

Finerenone was linked to hyperkalemia on its own. However, in FIDELIO-DKD, frequent potassium monitoring and hyperkalemia treatment measures reduced the effect of hyperkalemia, laying the groundwork for therapeutic usage of finerenone.