SGLT2 inhibitors – information for patients with heart failure, diabetes, and kidney disease
What you’ll learn by reading thisBy reading this information, you will understand:
- What SGLT2 inhibitors are and why they are prescribed
- How these medicines help the heart, blood sugar levels, and kidneys
- The most common and rare side effects, and what to look out for
- When to temporarily stop the medication if you become unwell
- When to seek medical advice or urgent help
Introduction
This page explains a group of medicines called SGLT2 inhibitors. These medicines are used to treat heart failure, type 2 diabetes, and chronic kidney disease.
The information below is intended to support discussions with your GP, pharmacist, or specialist team, not replace them. If anything is unclear or you have concerns, please speak to a healthcare professional.
What are SGLT2 inhibitors?
SGLT2 inhibitors are medicines that help the kidneys remove excess sugar from the blood by passing it into the urine. This also causes you to pass slightly more urine.
They were first developed to treat type 2 diabetes, but studies have shown they also protect the heart and kidneys, even in people who do not have diabetes.
Commonly used SGLT2 inhibitors include:
- Dapagliflozin (Forxiga®)
- Empagliflozin (Jardiance®)
These medicines are approved by NICE for use in:
- Heart failure with a weakened pumping function
- Type 2 diabetes
- Chronic kidney disease (CKD)
They may be prescribed whether or not you have diabetes.
How do SGLT2 inhibitors help?
For heart failure
SGLT2 inhibitors:
- Reduce the risk of heart failure getting worse
- Lower the chance of hospital admission
- Help improve symptoms such as breathlessness and fatigue
For type 2 diabetes
SGLT2 inhibitors:
- Lower blood glucose levels
- Reduce the risk of heart attack and stroke in people at higher risk
- Can help with modest weight loss and blood pressure reduction
For kidney disease
SGLT2 inhibitors:
- Slow the progression of chronic kidney disease
- Reduce protein loss in the urine
- Lower the risk of kidney failure and the need for dialysis
- Protect kidney function in people with and without diabetes
It is common to see a small drop in kidney function when starting treatment. This is expected, usually stabilises, and is not harmful. Long-term, these medicines protect the kidneys.
Are there any side effects?
Most people tolerate SGLT2 inhibitors well. Side effects are usually mild and manageable.
If you are worried about symptoms, contact your GP, pharmacist, or specialist team.
Common side effects
- Genital fungal infections (such as thrush)
Because more sugar passes into the urine, there is a higher risk of thrush around the genital area. Good hygiene and avoiding tight underwear can reduce the risk. These infections are usually easy to treat. Speak to a pharmacist or GP if symptoms occur. - Rash
- Dizziness
- Passing urine more frequently
- Low blood sugar (hypoglycaemia)
This mainly occurs if SGLT2 inhibitors are used with insulin or other diabetes medicines. Your diabetes team may adjust your treatment if needed.
Uncommon side effects
- Dehydration
Symptoms include thirst, dry mouth, dizziness, or a fast heartbeat. Drinking fluids usually helps. Your doctor may advise temporarily stopping the medicine if you become unwell.
Rare side effects
- Diabetic ketoacidosis (DKA)
This is a rare but serious condition caused by a build-up of acids (ketones) in the blood. It can happen even if blood sugar levels are normal.
Symptoms include nausea, vomiting, tummy pain, rapid breathing, dizziness, and thirst.
The risk is higher during illness, dehydration, prolonged fasting, heavy alcohol intake, or rapid insulin dose reduction. Seek medical advice before starting very low-carbohydrate or ketogenic diets.
Very rare but serious side effect
- Fournier’s gangrene
A rare, life-threatening infection affecting the genital or perineal area.
Seek urgent medical help if there is redness, swelling, pain, fever, or you feel generally unwell.
Sick day guidance
Should I stop this medicine if I become unwell?
If you are unwell enough to stop normal daily activities — especially with vomiting, diarrhoea, or fever — you should temporarily stop taking your SGLT2 inhibitor.
You can restart it once you are eating and drinking normally again.
If you are still unwell after 48 hours, seek advice from your GP, pharmacist, NHS 111, or your specialist team.
If you have diabetes, check your blood glucose more frequently during illness and seek advice if readings are very high or low.
When to seek urgent help
If you are acutely unwell or concerned about serious symptoms, contact NHS 111 or attend your local emergency department.
