Endocrine / Cardiovascular
SGLT2 inhibitors
"-flozin" drugs — Diabetes drugs that also protect the heart and kidneys — names ending in "-flozin".
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
SGLT2 inhibitors are used in type 2 diabetes and, increasingly, in heart failure and chronic kidney disease for their organ-protective effects — often regardless of diabetes status.
How it works
They block glucose reabsorption in the kidney, so excess glucose is passed in the urine. This lowers blood glucose and, through related effects on the heart and kidney, reduces heart-failure events and slows kidney decline.
In practice
In practice SGLT2 inhibitors have moved well beyond glucose control: they reduce heart-failure admissions and slow kidney disease, so they are now used in those conditions even without diabetes. Counsel on genital thrush and "sick day" rules, and be aware of a rare euglycaemic diabetic ketoacidosis — ketoacidosis that can occur with near-normal glucose, so it is easily missed.
Examples
Practical use
How to take it & use it well
- Take SGLT2 inhibitors such as dapagliflozin or empagliflozin once daily, with or without food, at around the same time each day.
- Drink enough fluids to stay well hydrated, as these medicines make you pass more urine.
- Follow sick-day rules: if you are unwell with vomiting, diarrhoea, dehydration or are not eating, you may be advised to pause the medicine temporarily.
- Keep up good genital hygiene, as the medicine can make thrush and urinary infections more likely.
- If you miss a dose, take it when you remember unless the next is nearly due, then skip it; do not double up.
- Know the warning signs of a serious problem and seek help if you feel very unwell with stomach pain, fast breathing or drowsiness.
Common uses
- Type 2 diabetes
- Heart failure (with or without diabetes)
- Chronic kidney disease
Monitoring
- Renal function (an expected small early dip), and effect on glucose where relevant
- Volume status and blood pressure
- Ketone awareness during illness
Weighing it up
Advantages & disadvantages
Advantages
- They lower blood sugar in type 2 diabetes without usually causing low sugars on their own.
- Many also protect the heart and kidneys, which is why they are used in heart failure and kidney disease too.
- They often lead to modest weight loss and a small drop in blood pressure.
- They are taken just once a day, which is convenient.
- They can reduce the risk of hospital admission for heart failure in suitable people.
Disadvantages
- They increase the risk of genital thrush and urinary tract infections.
- They can rarely cause a serious condition called diabetic ketoacidosis, sometimes even when sugar levels look normal.
- They make you pass more urine and can cause dehydration, especially if you are unwell.
- They are less suitable if your kidneys are significantly impaired.
- There is a rare risk of a serious genital infection, so any pain, swelling or redness there needs urgent attention.
Key safety principles
What to watch for
- Risk of euglycaemic diabetic ketoacidosis — withhold during acute illness, surgery and fasting ("sick day" rules).
- Genital and urinary infections are more common.
- Volume depletion, especially with diuretics in frail or older patients.
Key interactions
What to avoid or check alongside
- Water tablets and other medicines that remove fluid can add to dehydration and low blood pressure.
- Used with insulin or sulfonylureas, the risk of low blood sugar from those medicines may rise.
- Illness causing dehydration, and some other medicines, can raise the risk of ketoacidosis, which is why sick-day rules matter.
- Heavy alcohol use can increase the risk of ketoacidosis and should be limited.
- Tell your team about kidney medicines, as some combinations need closer monitoring.
Patient & carer advice
- Stop temporarily if you are acutely unwell, not eating, or before surgery — follow "sick day" advice
- Maintain genital hygiene; report thrush symptoms
- Seek help if you feel very unwell with nausea and breathlessness, even if glucose is normal
Use with
Related clinical calculators
Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
SGLT2 inhibitors: frequently asked questions
What are sick-day rules?
If you become unwell with vomiting, diarrhoea, fever or dehydration, you may be advised to temporarily stop the medicine until you recover, then restart. Your team can give you a personal plan.
Why do I keep getting thrush on this medicine?
These medicines remove sugar through the urine, which can encourage genital thrush and urinary infections. Good hygiene helps, and a pharmacist can advise on treatment.
Can this medicine cause a serious problem even if my sugar is normal?
Rarely, it can trigger diabetic ketoacidosis even when blood sugar is not very high. Seek urgent help if you feel very unwell with stomach pain, sickness, fast breathing or drowsiness.
Will it help me lose weight?
Many people lose a modest amount of weight on these medicines because sugar and some calories are lost in the urine, though results vary.
Is it only for diabetes?
No. Some are also used to protect the heart and kidneys in people with heart failure or chronic kidney disease, even without diabetes.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
Related guides
Need a custom medicines or prescribing resource?
We build evidence-led clinical references, calculators and decision aids for teams.