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Draft: not yet reviewed by a clinician

Use this page to prepare questions for your care team. It does not replace their advice. Your own targets and doses come from your nephrologist, diabetes team and renal dietitian.

Kidney-protecting medicines with type 1 diabetes

No doses on this page

This handbook never gives insulin or medicine doses and never tells you to change one. Your prescriber sets every dose and every change, and writes down when to pause a medicine and when to restart it. A low blood glucose is always treated straight away: see Treating a low and Get help now.

In short

If you have albumin in your urine, medicines can slow kidney damage. The first choice is an ACE inhibitor or an ARB (KDIGO 2024, recommendation 3.6.3). Since September 2026, finerenone (Kerendia) is also approved in the US for adults with kidney disease and type 1 diabetes (Kerendia label). These medicines can raise blood potassium and cause a small, expected rise in creatinine, so each comes with blood tests. Two other kinds of medicine, SGLT2 inhibitors and GLP-1 receptor agonists, protect the kidneys in type 2 diabetes, but their benefit and safety have not been established in type 1 diabetes, and none is approved to treat it. Ask before any change, and never stop one on your own.

Your numbers

Check When The usual rule Source
Blood pressure, creatinine and potassium 2–4 weeks after starting or raising an ACE inhibitor or ARB your team looks at all three together KDIGO 2024, practice point 3.6.2
Creatinine in the first 4 weeks a rise up to 30 % is expected; keep taking the medicine unless it rises more KDIGO 2024, practice point 3.6.4; ADA 2026 §11, recommendation 11.6d
Potassium before finerenone before the first tablet not started if potassium is above 5.0 mEq/L (5.0 mmol/L) Kerendia label
Potassium on finerenone 4 weeks after starting or a change, then regularly your team adjusts or pauses it if potassium is high Kerendia label
eGFR for finerenone before starting starting is not recommended below 25 mL/min/1.73 m² Kerendia label
Blood pressure every visit usually under 130/80 mmHg; a top number under 120 if it is measured the standard way at the clinic and you feel well with it ADA 2026 §11, recommendation 11.5; KDIGO 2024, recommendation 3.4.1
Urine albumin (UACR) at least yearly lower is better UACR

For potassium, mEq/L and mmol/L are the same number.

What a 30 % rise looks like:

Before After 3 weeks Rise What happens
creatinine 1.50 mg/dL 1.80 mg/dL 20 % expected; keep taking it
creatinine 1.50 mg/dL 2.10 mg/dL 40 % your team rechecks and reviews the medicine
Before After 3 weeks Rise What happens
creatinine 133 µmol/L 159 µmol/L 20 % expected; keep taking it
creatinine 133 µmol/L 186 µmol/L 40 % your team rechecks and reviews the medicine

ACE inhibitors and ARBs

What they are. ACE inhibitor names usually end in "-pril" (such as lisinopril or ramipril). ARB names end in "-sartan" (such as losartan). They relax the blood vessels that leave each kidney filter, which lowers the pressure inside the filter and the albumin leak.

Who should take one. KDIGO recommends one for people with diabetes and moderately or severely increased albuminuria (A2 or A3) (KDIGO 2024, recommendation 3.6.3; KDIGO 2022, recommendation 1.2.1). The ADA says the same for people with diabetes, high blood pressure and albuminuria (ADA 2026 §11, recommendation 11.6a).

Why the creatinine rises. Lower pressure in the filters means a small drop in eGFR at first. It is a sign the medicine is working, not damage. KDIGO says to keep going unless creatinine rises more than 30 % within 4 weeks (KDIGO 2024, practice point 3.6.4).

Rules that keep you safe:

  • Never take an ACE inhibitor and an ARB together. The combination is harmful (KDIGO 2024, recommendation 3.6.4).
  • High potassium can often be handled by other steps that lower potassium, such as diet changes your team suggests or a medicine that removes potassium, rather than by stopping the medicine (KDIGO 2024, practice point 3.6.3; Potassium).
  • These medicines are usually continued even when eGFR falls below 30 (KDIGO 2024, practice point 3.6.7). Your team may lower or stop one for low blood pressure that causes symptoms, potassium that stays high despite treatment, or near kidney failure (practice point 3.6.5).
  • On sick days, pause one only if your written plan says so, and restart when it says (Sick days).

Pregnancy

ACE inhibitors and ARBs can harm an unborn baby. Finerenone has not been studied in pregnancy and harmed unborn animals, and the ADA lists this group of medicines (MRAs), with SGLT2 inhibitors, among the kidney medicines to avoid in pregnancy. If you could become pregnant, use reliable contraception while taking any of them, and talk to your team before trying for a baby. If you become pregnant, call your team straight away (KDIGO 2022, practice point 1.2.4; KDIGO 2024, practice point 4.1.4; ADA 2026 §11, recommendation 11.10; Kerendia label, section 8.1). Pregnancy with kidney disease needs specialist care (UK Kidney Association 2019; Sex, fertility and pregnancy).

Finerenone (Kerendia)

What it is. A non-steroidal mineralocorticoid receptor antagonist (MRA), usually taken alongside an ACE inhibitor or ARB. In September 2026 the FDA approved it for adults with kidney disease and type 1 diabetes "to reduce urinary albumin-to-creatinine ratio (UACR)" (Kerendia label).

What the trial showed. FINE-ONE studied 242 adults with type 1 diabetes for 6 months. All took an ACE inhibitor or ARB, had an eGFR of 25–89 and a UACR of 200 mg/g (about 23 mg/mmol) or more, and people taking SGLT2 inhibitors or GLP-1 receptor agonists were left out (FINE-ONE; Kerendia label, section 14.2):

Result Finerenone Placebo
Fall in UACR 34 % 12 % (so 25 % more with finerenone)
High potassium 10.1 % of people 3.3 %
eGFR change at 6 months −5.6 mL/min/1.73 m² −2.7 mL/min/1.73 m²

The early eGFR dip came back toward the starting level after the medicine was stopped. Only 2 people (1.7 %) stopped finerenone because of high potassium (FINE-ONE).

Living with it:

  • No grapefruit or grapefruit juice (Kerendia label). The FDA notes that Seville oranges, pomelos and tangelos can act like grapefruit with some medicines, so ask your pharmacist about them (FDA).
  • Some medicines must not be combined with it, for example the antifungal itraconazole. Others, such as the antibiotic erythromycin or the heart medicine verapamil, mean extra potassium checks (Kerendia label). Tell every prescriber and pharmacist you take it.
  • Ask before using a salt substitute or a potassium supplement (Kerendia label, section 17).
  • Do not breastfeed while taking it, or for 1 day after the last tablet (Kerendia label).

SGLT2 inhibitors: not for type 1 without a plan

SGLT2 inhibitors (such as dapagliflozin or empagliflozin) protect the kidneys and heart in type 2 diabetes and in kidney disease without diabetes. People with type 1 diabetes were left out of those trials (KDIGO 2024, research recommendations). In type 1 diabetes they raise the risk of DKA 5 to 17 times (ADA 2026 §6), and the label says they are not recommended to treat glucose in type 1 diabetes (Farxiga label). In recent years they have caused most cases of DKA with near-normal glucose (2024 consensus).

If your team still prescribes one for you, ask for:

  • a blood ketone meter, and checks whenever you feel unwell, even if glucose looks normal (Farxiga label);
  • a written rule for stopping it on sick days and before planned surgery, and for restarting it (KDIGO 2024, practice points 4.3.2–4.3.3; Sick days).

GLP-1 receptor agonists

Semaglutide (Ozempic) has a kidney approval, but only for adults with type 2 diabetes (Ozempic label; ADA 2026 §11, recommendation 11.7b). These medicines are not approved for type 1 diabetes. If one is suggested, for example for weight, ask how your insulin plan and your risk of lows will change.

Other ways to protect your kidneys

  • Blood pressure in range, usually under 130/80 mmHg (ADA 2026 §11, recommendation 11.5).
  • A statin for cholesterol: KDIGO recommends one for people with type 1 or type 2 diabetes and kidney disease (KDIGO 2022). If you are on dialysis, ask whether this applies to you.
  • Less salt: KDIGO suggests under 2,000 mg of sodium a day, and less sodium helps ACE inhibitors and ARBs work better (KDIGO 2024, recommendation 3.3.2.1; KDIGO 2022, recommendation 3.1.2; Sodium).
  • Glucose in range, without too many lows (How kidney disease changes type 1 diabetes).

What to do

  • If your UACR is 30 mg/g (3 mg/mmol) or more, ask whether you should take an ACE inhibitor or ARB.
  • Get your blood test 2–4 weeks after starting or changing one. Put the date in your phone.
  • Do not stop because creatinine went up a little. Ask your team what the number means.
  • Ask whether finerenone fits you, and how often your potassium will be checked.
  • Keep potassium in check: no salt substitutes, and follow your potassium plan (Potassium).
  • Add each new lab result to the app's Labs so you can see the trend (Targets and warnings).
  • Keep your medicine list up to date.

Examples

  • An expected rise. Maya starts an ACE inhibitor. Three weeks later her creatinine has gone from 1.50 to 1.70 mg/dL (133 to 150 µmol/L), a 13 % rise. Her potassium is 4.8. Her team says to keep going.
  • Potassium creeping up. Dev takes an ARB and starts finerenone. At 4 weeks his potassium is 5.4. His team checks his diet, reviews his other medicines and repeats the test. He switches from orange juice to cranberry juice cocktail for lows, and stops using "lite" salt.
  • Planning a pregnancy. Priya wants a baby next year. She tells her nephrologist now, so they can plan a switch before she tries to conceive.

Ask your care team

  1. Should I be on an ACE inhibitor or ARB? Am I at the dose that protects my kidneys best?
  2. When is my next blood test, and what creatinine and potassium numbers would worry you?
  3. Is finerenone right for me? What happens if my potassium goes up?
  4. Are any of my other medicines a problem with finerenone?
  5. Which of these medicines should I pause on a sick day, and when do I restart?
  6. I might want to get pregnant. What should we change, and when?

Get help now if…

  • Swelling of the lips, tongue or throat, or trouble breathing or swallowing, after a new medicine: call 911 (or your local emergency number). The Kerendia label lists this kind of reaction (angioedema) (Kerendia label).
  • Fainting, a very slow or irregular pulse, or a lab potassium of 6.5 mmol/L or more: call 911 (KDIGO 2024, Table 28; MedlinePlus).
  • A lab potassium of 6.0–6.4 mmol/L, or dizziness when you stand up (low blood pressure is a known side effect of these medicines): call your team today (KDIGO 2024, Table 28; Kerendia label). See Get help now and Blood potassium.

Sources

Not yet reviewed by a clinician. Facts and sources last checked 2026-10-06.