Finerenone in heart failure: potassium and dose

A 74-year-old woman is discharged after a hospitalization for decompensated heart failure. The echocardiogram shows a left ventricular ejection fraction of 55, with an enlarged left atrium. She takes furosemide, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor and losartan. At discharge, the estimated glomerular filtration rate (eGFR) is 48 mL/min/1.73 m² and potassium is 4.6 mEq/L. She also takes itraconazole for a nail fungal infection and enjoys grapefruit juice at breakfast. The cardiologist considers adding finerenone. The scene is fictional and was written for teaching.

This text uses the case as a clinical reasoning scenario for students and health professionals. Finerenone (brand name Kerendia) is a nonsteroidal mineralocorticoid receptor antagonist. It was already used in chronic kidney disease with type 2 diabetes and gained an indication in heart failure with ejection fraction of 40 or more. The challenge lies in the details: the dose depends on kidney function, potassium guides each adjustment and some interactions rule out its use. The text does not replace the package insert in your country or your institution's protocol. If you play the case of the day on NEXO, you will recognize the challenge: deciding with clues that arrive in sequence.

Key points

• The FDA approved the indication in heart failure with ejection fraction of 40 or more on July 11, 2025; the EMA lists the same indication in adults with symptomatic chronic heart failure.
• In FINEARTS-HF, with 6001 patients, finerenone reduced the outcome of cardiovascular death and heart failure events, with a rate ratio of 0.84.
• The starting dose is 10 mg with eGFR from 25 to less than 60 and 20 mg with eGFR of 60 or more; the targets are 20 mg and 40 mg.
• The drug is not started with potassium above 5.0 mEq/L or with eGFR below 25.
• Potassium and eGFR should be measured 4 weeks after starting and after each dose change.
• Strong CYP3A4 inhibitors, such as itraconazole, are contraindicated; grapefruit should be avoided.

Why this is a reasoning scenario

Heart failure with mildly reduced or preserved ejection fraction is common in older people and has few options that change outcomes. In FINEARTS-HF, participants' ages ranged from 40 to 97 years, 64 percent were 70 or older and 24 percent were 80 or older (Chimura and colleagues, 2024). The patient in the scene resembles those who entered the study: older, with a recent hospitalization, reduced kidney function and use of a loop diuretic (US Kerendia package insert, revised 9/2026).

The scenario is good for training because it brings together indication, dosing by kidney function, potassium, interactions and patient guidance. Those working in the emergency department, the ward or the pharmacy may meet this patient with high potassium, rising creatinine or low blood pressure. The post on signs, symptoms and history shows how to ask about medications and foods, and the post on differential diagnosis helps to think about other causes of high potassium.

What the scene teaches

The scene trains six habits. The first is to confirm the indication: symptomatic heart failure with ejection fraction of 40 or more. The second is to measure potassium and eGFR before starting. The third is to choose the starting dose by eGFR. The fourth is to review all medications for CYP3A4 inhibitors and inducers. The fifth is to schedule tests in 4 weeks. The sixth is to teach the patient about foods, supplements and warning signs.

What is not at stake

The text does not discuss the full diagnosis of heart failure or the choice of other therapies. Long-term management belongs to the team following the patient. The post on clinical decision-making helps to think about the sequence of tests.

How finerenone works and what FINEARTS-HF showed

Finerenone is a nonsteroidal, selective mineralocorticoid receptor antagonist (US label for Kerendia, revised 9/2026). It blocks activation of this receptor by aldosterone and cortisol, with no relevant affinity for androgen, progesterone, estrogen and glucocorticoid receptors (US label for Kerendia, revised 9/2026). Excessive activation of the mineralocorticoid receptor appears to contribute to fibrosis and inflammation (US label for Kerendia, revised 9/2026).

The FINEARTS-HF study

FINEARTS-HF was a randomized, double-blind, placebo-controlled study in adults with heart failure in functional class II to IV and ejection fraction of 40 or more (US label for Kerendia, revised 9/2026). Patients needed an eGFR of at least 25 and potassium of up to 5.0 mEq/L (US label for Kerendia, revised 9/2026). A total of 6001 patients were analyzed, 3003 with finerenone and 2998 with placebo, followed for a median of 2.7 years (US label for Kerendia, revised 9/2026). More than half, 54 percent, had a heart failure event in the previous 3 months, and 20 percent were randomized during hospitalization or up to 7 days after the event (US label for Kerendia, revised 9/2026).

Mean age was 72 years, 46 percent were women, mean ejection fraction was 53 and 48 percent had an eGFR below 60 (US label for Kerendia, revised 9/2026). Most were on a loop diuretic (87 percent), and 14 percent were on an SGLT2 inhibitor (US label for Kerendia, revised 9/2026). At 6 months, about 65 percent reached the target dose (US label for Kerendia, revised 9/2026).

Finerenone reduced the primary composite outcome of cardiovascular death and total heart failure events, with a rate ratio of 0.84 and a confidence interval of 0.74 to 0.95 (US label for Kerendia, revised 9/2026). Total heart failure events also fell, with a rate ratio of 0.82 (US label for Kerendia, revised 9/2026). On the EMA page, the outcome occurred in 21 percent of patients on finerenone (624 of 3003) and in 24 percent on placebo (719 of 2998) (EMA, Kerendia). The effect was consistent across prespecified subgroups, including sex, ejection fraction, functional class, eGFR, time since the last event, use of an SGLT2 inhibitor and diabetes (US label for Kerendia, revised 9/2026).

The subgroup analyses

Several prespecified analyses detailed the effect in different groups. The benefit was similar across all age ranges, including in people in their eighties (Chimura and colleagues, 2024). It was similar in women and men, in a study in which about 45.5 percent were women (Chimura and colleagues, 2025). Frailty was common and was associated with a worse course, but it did not change the effect of finerenone (Butt and colleagues, 2025). There was also no difference in effect between those with and without atrial fibrillation (Matsumoto and colleagues, 2025).

The analysis by ejection fraction studied the whole spectrum included in the study (Docherty and colleagues, 2025). Patients whose ejection fraction had previously been below 40 and improved had a risk similar to the rest of the study and a comparable benefit (Pabon and colleagues, 2025). The authors note that an improvement in ejection fraction does not mean the heart has recovered (Pabon and colleagues, 2025). Finerenone also reduced intensification of oral diuretics in the outpatient setting, which occurred in 21 percent of patients and was associated with a worse prognosis (Cunningham and colleagues, 2025).

With or without an SGLT2 inhibitor

The effect of finerenone on cardiovascular death and worsening heart failure was consistent with or without use of an SGLT2 inhibitor, and no new safety signals emerged with the combination (Vaduganathan and colleagues, 2025). This matters for the patient in the scene, who is already on an SGLT2 inhibitor. In the pooled FINE-HEART analysis, with 18,991 participants from three studies, finerenone did not significantly reduce cardiovascular death, but death from any cause fell with nominal significance (Vaduganathan and colleagues, 2024).

Before heart failure: the kidney studies

Finerenone reached chronic kidney disease with type 2 diabetes first. In the analysis of cardiovascular outcomes in patients with chronic kidney disease and type 2 diabetes, the cardiovascular outcome included cardiovascular death, myocardial infarction, stroke and hospitalization for heart failure (Filippatos et al., 2021). In the pooled FIDELITY analysis, adverse effects linked to high potassium were more frequent with finerenone (14.0 percent) than with placebo (6.9 percent), with no deaths from this cause (Agarwal et al., 2022). These data help to understand the safety profile that was repeated in heart failure.

Regulatory status: FDA and EMA

United States. The FDA approved Kerendia on July 9, 2021, under NDA 215341, as a new molecular entity with priority review (Drugs@FDA, NDA 215341). The heart failure indication came through supplement 9, classified as a new indication, on July 11, 2025 (Drugs@FDA, NDA 215341). A supplement dated September 16, 2026 brought a label change with clinical data (Drugs@FDA, NDA 215341). In the label revised in 9/2026, the indication includes adults with heart failure and an ejection fraction of 40 or more, to reduce the risk of cardiovascular death, hospitalization for heart failure and urgent visits for heart failure (US Kerendia label, revised in 9/2026). The same label keeps the indication in chronic kidney disease with type 2 diabetes and includes chronic kidney disease with type 1 diabetes (US Kerendia label, revised in 9/2026).

European Union. Kerendia received a marketing authorization valid throughout the European Union on February 16, 2022 (EMA, Kerendia). The EMA page lists two indications: chronic kidney disease with albuminuria associated with type 2 diabetes in adults and symptomatic chronic heart failure with an ejection fraction of 40 or more in adults (EMA, Kerendia). The medicine is under additional monitoring, and the EPAR summary was updated on May 7, 2026 (EMA, Kerendia).

Other countries. The exact indication and access depend on the local agency. The patient in the scene would fall within the US and European indications, as long as she has symptoms and an ejection fraction of 40 or more.

Contraindications

The US label lists three contraindications (US Kerendia label, revised in 9/2026):

• Hypersensitivity to any component of the product.
• Use together with strong CYP3A4 inhibitors.
• Adrenal insufficiency.

The label uses itraconazole as an example of a strong CYP3A4 inhibitor (US Kerendia label, revised in 9/2026). For the patient in the scene, finerenone cannot be started while she is taking this antifungal. It is worth waiting for the treatment to end or discussing another option for the fungal infection with whoever prescribed it.

Starting dose, target and follow-up tests

Before starting, the label calls for measuring potassium and eGFR (US Kerendia label, revised in 9/2026). The medicine should not be started if potassium is above 5.0 mEq/L (US Kerendia label, revised in 9/2026). The starting dose depends on eGFR, and so does the target dose in heart failure (US Kerendia label, revised in 9/2026).

eGFR at the start (mL/min/1.73 m²)	Starting dose	Target dose in heart failure	Source
60 or more	20 mg once a day	40 mg once a day	(US Kerendia label, revised in 9/2026)
25 to less than 60	10 mg once a day	20 mg once a day	(US Kerendia label, revised in 9/2026)
Less than 25	Starting not recommended	Not applicable	(US Kerendia label, revised in 9/2026)

The patient in the scene has an eGFR of 48. If the itraconazole has already ended and potassium remains at 4.6 mEq/L, she would start with 10 mg and have a target of 20 mg. In FINEARTS-HF, patients started exactly like this: 10 mg with eGFR from 25 to less than 60 and 20 mg with eGFR of 60 or more (US Kerendia label, revised in 9/2026).

Follow-up tests

Potassium and eGFR should be measured 4 weeks after starting and 4 weeks after each dose change, and then periodically (US Kerendia label, revised 9/2026). In the first month, a small rise in creatinine is expected, of less than 0.1 mg/dL, with a drop of 2 to 3 mL/min/1.73 m² in eGFR, which then stabilizes and is reversible (US Kerendia label, revised 9/2026). Uric acid may also rise a little (US Kerendia label, revised 9/2026).

Tablets and missed doses

The tablets come in 10, 20 and 40 mg and can be crushed for those who have trouble swallowing (US Kerendia label, revised 9/2026). If the patient forgets a dose, she should take it the same day; if she only remembers the next day, she skips the missed dose and follows the normal schedule (US Kerendia label, revised 9/2026). It is worth writing this on the prescription, because older patients on many medicines often double the dose by mistake.

Older adults and the liver

In FINEARTS-HF, 79 percent of patients were 65 or older and 43 percent were 75 or older, and the label does not require dose adjustment for age (US Kerendia label, revised 9/2026). In severe hepatic impairment (Child-Pugh C), use should be avoided; in moderate impairment (Child-Pugh B), it is worth monitoring potassium more often (US Kerendia label, revised 9/2026). Breastfeeding is not recommended during treatment (US Kerendia label, revised 9/2026).

Potassium: the table that guides each adjustment

In heart failure, the label provides an adjustment table guided by the measured potassium (US Kerendia label, revised 9/2026). It applies to each follow-up test and to each decision to raise or lower the dose.

Potassium (mEq/L)	Current dose of 10 mg	Current dose of 20 mg	Current dose of 40 mg
Less than 5.0	Raise to 20 mg	Keep 20 mg if baseline eGFR was below 60; if it was 60 or more, raise to 40 mg	Keep 40 mg
5.0 to less than 5.5	Keep	Keep	Keep
5.5 to less than 6.0	Hold and restart at 10 mg when potassium falls below 5.5	Reduce to 10 mg	Reduce to 20 mg
6.0 or more	Hold	Hold	Hold

Table source: (US Kerendia label, revised 9/2026). After holding for potassium of 6.0 or more, the medicine can be restarted at 10 mg when potassium falls below 5.5 (US Kerendia label, revised 9/2026). There are two extra rules. If eGFR has fallen more than 30 percent from the previous value, the dose should be kept, without raising it (US Kerendia label, revised 9/2026). If repeat potassium remains at 5.5 or more, restarting at 10 mg should only occur when potassium falls below 5.0 (US Kerendia label, revised 9/2026).

How often potassium rises

In FINEARTS-HF, potassium above 5.5 mmol/L was more frequent with finerenone, and potassium below 3.5 mmol/L was less frequent (Vardeny and colleagues, 2025). Potassium above 6.0 was uncommon, but also more often seen with finerenone (Vardeny and colleagues, 2025). Hospitalizations for high potassium were rare, 0.5 percent with finerenone and 0.2 percent with placebo, and there were no deaths from this cause (Vardeny and colleagues, 2025). A meta-analysis confirmed a higher risk of high potassium with finerenone in heart failure, with a relative risk of 2.07 (Yu and colleagues, 2025).

Low potassium also matters

Values at both extremes, below 3.5 and above 5.5 mmol/L, were associated with more events in both groups (Vardeny and colleagues, 2025). In an analysis that combined potassium and kidney function, patients with potassium above 4.5 mmol/L had fewer heart failure events and fewer deaths than those with potassium up to 4.5 mmol/L (Ferreira and colleagues, 2025). An eGFR below 60 increased the risk of events, with little influence from potassium (Ferreira and colleagues, 2025). In other words, the goal is not to keep potassium as low as possible, but within the safe range.

Applying it to the patient

Suppose that, 4 weeks after starting 10 mg, potassium is 5.1 mEq/L. According to the table, the 10 mg dose should be maintained. If it is 4.8 mEq/L, the dose can go up to 20 mg, its target. If it reaches 5.7 mEq/L, finerenone should be suspended and restarted at 10 mg when potassium falls below 5.5. The post about diagnostic pause reminds you to check the test and the current dose before deciding.

Kidney function, blood pressure and interactions

In heart failure, worsening kidney function was more frequent with finerenone (US Kerendia label, revised 9/2026). Kidney-related effects occurred in 18 percent with finerenone and 12 percent with placebo (US Kerendia label, revised 9/2026). Among them, the label lists renal failure (7 and 4 percent), eGFR decrease (5 and 4 percent), acute kidney injury (4 and 2 percent) and kidney failure (3 and 2 percent) (US Kerendia label, revised 9/2026). These effects led to a dose change in 9 percent with finerenone and 4 percent with placebo, and to hospitalization in 2.0 and 1.3 percent (US Kerendia label, revised 9/2026). The label advises considering delaying the dose increase or interrupting the drug when kidney function worsens (US Kerendia label, revised 9/2026).

Blood pressure

Finerenone reduced systolic blood pressure early and persistently in FINEARTS-HF (Ostrominski and colleagues, 2026). The benefit on cardiovascular death and heart failure events was consistent across all baseline blood pressure ranges and appeared independent of the blood pressure drop (Ostrominski and colleagues, 2026). Baseline blood pressure did not change the safety profile (Ostrominski and colleagues, 2026). In the kidney trials, hypotension occurred in 4.6 percent with finerenone and 3.0 percent with placebo (US Kerendia label, revised 9/2026). For the older patient in the scene, it is worth measuring blood pressure standing and asking about dizziness, especially if the diuretic is adjusted.

Other effects

In the kidney trials, hyponatremia occurred in 1.3 percent with finerenone and 0.7 percent with placebo (US Kerendia label, revised 9/2026). Hospitalizations for high potassium were 0.9 and 0.2 percent, and discontinuation of the drug for this reason was 1.7 and 0.6 percent (US Kerendia label, revised 9/2026). The drug is not removed by dialysis, because about 90 percent circulates bound to proteins (US Kerendia label, revised 9/2026).

Interactions that change management

Finerenone is metabolized by CYP3A4, and the label organizes the interactions as follows (US Kerendia label, revised 9/2026):

• Strong CYP3A4 inhibitors, such as itraconazole: use contraindicated.
• Grapefruit and grapefruit juice: avoid.
• Moderate or weak CYP3A4 inhibitors: monitor potassium when starting or adjusting either drug.
• Strong or moderate CYP3A4 inducers: avoid, because they reduce the effect.
• Drugs or supplements that raise potassium: monitor potassium more often.
• Sensitive CYP2C8 substrates: monitor when the dose is 40 mg, because finerenone is a weak inhibitor of this enzyme.

The patient in the scene has two interactions on the list: itraconazole and grapefruit juice. She also takes losartan, and the label calls for more frequent potassium monitoring with drugs that raise it (US Kerendia label, revised 9/2026). This does not prevent use, but it reinforces monitoring at 4 weeks. The label advises the patient to talk to the doctor before using potassium supplements or salt substitutes containing potassium (US Kerendia label, revised 9/2026). The post about interprofessional clinical reasoning shows why the pharmacy helps to find these interactions.

When the patient worsens

If the patient arrives with weakness, palpitations or electrocardiogram changes, potassium should be checked right away. If she arrives with vomiting, diarrhea or low fluid intake, kidney function can worsen quickly, and the dose should be reviewed. The post about clinical deterioration on the ward shows how to escalate when vital signs change.

What to advise at discharge

Discharge instructions must be short and concrete. The patient should know the name of the medicine, the dose and the reason. She should know that potassium and creatinine need to be checked in 4 weeks, and the date should be written down. She should avoid grapefruit juice, salt substitutes and potassium supplements without talking to the team. She should tell any doctor who is about to prescribe a new medicine that she takes finerenone, because CYP3A4 inhibitors and inducers change the approach (US Kerendia label, revised 9/2026). And she should know which signs call for contact: weakness, palpitations, dizziness on standing or a drop in urine output.

How NEXO helps train this reasoning

In NEXO, the case of the day is fictional, with a real clinical presentation and up to six progressive clues, and you propose the diagnosis by looking for the ICD-10 code. Finerenone is a good exercise because a potassium value, an eGFR or a new antifungal changes the approach. The post on case-based learning explains why this format fixes knowledge, and the post on diagnostic uncertainty helps when the data do not add up. The post on simulation of patient encounters shows how to train discharge instructions.

Three exercises with cases

Change the eGFR. State the starting dose and the target if the eGFR were 65.

Change the potassium. State what to do if, on 20 mg, the potassium were 5.6 mEq/L.

Change the medicine. State what to do if the patient started a strong CYP3A4 inducer.

The limits on using the game are described on the NEXO economy page. If you research teaching of clinical reasoning, the page for researchers explains how to get in touch. Professionals who write or review cases find information under curation and creators, and institutions can learn about the proposal on the partnerships page.

Frequently asked questions

Does finerenone replace spironolactone?

They are different medicines. Finerenone is non-steroidal and selective, and the approved indication in heart failure applies to ejection fraction of 40 or more (US Kerendia label, revised 9/2026).

What is the starting dose?

Per the label, 10 mg with eGFR from 25 to under 60 and 20 mg with eGFR of 60 or more, once a day (US Kerendia label, revised 9/2026).

When should potassium be checked?

Before starting, 4 weeks after starting, 4 weeks after each dose change and then periodically (US Kerendia label, revised 9/2026).

Can it be used with an SGLT2 inhibitor?

Yes. In FINEARTS-HF, the effect was consistent with or without an SGLT2 inhibitor (Vaduganathan et al., 2025).

Which food should be avoided?

Grapefruit and grapefruit juice (US Kerendia label, revised 9/2026).

Final checklist

• I confirmed symptomatic heart failure with ejection fraction of 40 or more.
• I measured potassium and eGFR before starting.
• I checked that potassium is up to 5.0 mEq/L and eGFR is 25 or more.
• I chose the starting dose and the target by eGFR.
• I reviewed CYP3A4 inhibitors and inducers, grapefruit and potassium sources.
• I scheduled potassium and eGFR in 4 weeks.
• I used the potassium table for each adjustment.
• I gave guidance on a missed dose, dizziness and warning signs.

Want to practice reasoning with progressive clues? Play the case of the day.

References

1. Agarwal R, Filippatos G, Pitt B, et al. Cardiovascular and kidney outcomes with finerenone in patients with type 2 diabetes and chronic kidney disease: the FIDELITY pooled analysis. Eur Heart J. 2022. PMID 35023547.
2. Bayer HealthCare Pharmaceuticals. KERENDIA® (finerenone) tablets, for oral use. Prescribing Information. Revised 9/2026. Accessed 10/24/2026. Official source.
3. Butt JH, Jhund PS, Henderson AD, et al. Finerenone According to Frailty in Heart Failure: A Prespecified Analysis of the FINEARTS-HF Randomized Clinical Trial. JAMA Cardiol. 2025. PMID 40531488.
4. Chimura M, Petrie MC, Schou M, et al. Finerenone Improves Outcomes in Patients With Heart Failure With Mildly Reduced or Preserved Ejection Fraction Irrespective of Age: A Prespecified Analysis of FINEARTS-HF. Circ Heart Fail. 2024. PMID 39342655.
5. Chimura M, Wang X, Jhund PS, et al. Finerenone in Women and Men With Heart Failure With Mildly Reduced or Preserved Ejection Fraction: A Secondary Analysis of the FINEARTS-HF Randomized Clinical Trial. JAMA Cardiol. 2025. PMID 39550721.
6. Cunningham JW, Chatur S, Claggett BL, et al. Finerenone and Outpatient Worsening Heart Failure With Mildly Reduced or Preserved Ejection Fraction: A Secondary Analysis of the FINEARTS-HF Randomized Clinical Trial. JAMA Cardiol. 2025. PMID 40009358.
7. Docherty KF, Henderson AD, Jhund PS, et al. Efficacy and Safety of Finerenone Across the Ejection Fraction Spectrum in Heart Failure With Mildly Reduced or Preserved Ejection Fraction: A Prespecified Analysis of the FINEARTS-HF Trial. Circulation. 2025. PMID 39342512.
8. European Medicines Agency. Kerendia. EPAR. Accessed on 24/10/2026. Official source.
9. Ferreira JP, Vaduganathan M, Claggett BL, et al. Interplay of serum potassium and kidney function with finerenone in heart failure with mildly reduced or preserved ejection fraction: Findings from FINEARTS-HF. Eur J Heart Fail. 2025. PMID 41039732.
10. Filippatos G, Anker SD, Agarwal R, et al. Finerenone and Cardiovascular Outcomes in Patients With Chronic Kidney Disease and Type 2 Diabetes. Circulation. 2021. PMID 33198491.
11. Matsumoto S, Henderson AD, Jhund PS, et al. Finerenone and Atrial Fibrillation in Heart Failure: A Secondary Analysis of the FINEARTS-HF Randomized Clinical Trial. JAMA Cardiol. 2025. PMID 40156827.
12. Ostrominski JW, Claggett BL, Kulac IJ, et al. Finerenone and Blood Pressure in Heart Failure With Mildly Reduced or Preserved Ejection Fraction: The FINEARTS-HF Randomized Clinical Trial. JAMA Cardiol. 2026. PMID 42418169.
13. Pabon MA, Vardeny O, Vaduganathan M, et al. Finerenone in Heart Failure With Improved Ejection Fraction: The FINEARTS-HF Randomized Clinical Trial. JAMA Cardiol. 2025. PMID 40397470.
14. U.S. Food and Drug Administration. Drugs@FDA: FDA-Approved Drugs. NDA 215341, Kerendia. Accessed on 24/10/2026. Official source.
15. Vaduganathan M, Filippatos G, Claggett BL, et al. Finerenone in heart failure and chronic kidney disease with type 2 diabetes: FINE-HEART pooled analysis of cardiovascular, kidney and mortality outcomes. Nat Med. 2024. PMID 39218030.
16. Vaduganathan M, Claggett BL, Kulac IJ, et al. Effects of the Nonsteroidal MRA Finerenone With and Without Concomitant SGLT2 Inhibitor Use in Heart Failure. Circulation. 2025. PMID 39340828.
17. Vardeny O, Vaduganathan M, Claggett BL, et al. Finerenone, Serum Potassium, and Clinical Outcomes in Heart Failure With Mildly Reduced or Preserved Ejection Fraction. JAMA Cardiol. 2025. PMID 39550716.
18. Yu W, Luo F, Rao J, et al. Adverse effects of finerenone in patients with heart failure: a systematic review and meta-analysis. Front Cardiovasc Med. 2025. PMID 40495987.