Who is this information for?
This is designed for people who are taking or are about to take an SGLT-2 inhibitor drug to improve the treatment of your diabetes, kidney, or heart disease.
The name of these drugs end with ‘gliflozin’. Examples include:
- empagliflozin (Jardiance®)
- dapagliflozin (Forxiga®)
- canagliflozin (lnvokana®)
- ertugliflozin (Steglatro®)
This group or ‘family’ of drugs are called SGLT2 inhibitors, also known as a ‘flozin’ or ‘gliflozin’.
Like all medicines they can have side effects, and this information is designed to help you to understand more and to know what to be aware of.
Research has found that there are some very rare but important side effects which appear to be associated with taking this medication. It is important to note that these side effects are very rare and do not outweigh the benefits to using this medication. You should be aware of these potential side effects as if they are not identified early, they can be extremely dangerous.
What are the common side effects?
Many people will not experience side effects with these drugs. However, like all medicines, ‘flozins’ can cause side effects.
Some common side effects include:
- Dehydration: You may find you make more urine when you take these drugs. This can sometimes lead to dehydration. This is more likely for people also taking water tablets (diuretics) such as Furosemide, Bumetanide or Metolazone. It is important that you drink water if dehydrated. Speak to your doctor if you are taking water tablets whilst on an SGLT2 inhibitor.
- Low blood sugar (hypoglycaemia): This is more likely to happen in people with diabetes that are already taking other diabetes medications. When you start an SGLT2 inhibitor, a change in your diabetes medicines might be needed. Your prescriber will review your other medication when prescribing a ‘flozin’ and advise you if any changes are needed.
- Urine and fungal infections: You may get urine and fungal infections. This includes thrush around the vagina or penis. These should be reported to your doctor, pharmacist or nurse and are usually treatable. Maintaining good hygiene of the genital area should reduce your risk.
What are the rare but serious side effects?
Far less common, but important side effects of SGLT2 inhibitors include:
- Ketoacidosis: Acids called ketones can build up in the bloodstream. You may feel sick, dehydrated, confused, drowsy, dizzy, breathless and your breath may smell like nail varnish remover. Ketoacidosis risk is increased if you go for long periods without eating, become dehydrated, or drink excess alcohol. Very low carbohydrate diets should be avoided. You should seek urgent medical attention if you have any of these symptoms or think you may have developed ketoacidosis.
- Foot disease: There may be a small theoretical risk of worsening foot ulcers, gangrene or severe foot infections or toe amputations, particularly among people with diabetes or who have or have had foot disease. People with diabetes should continue regular preventative foot care including podiatry appointments and seek medical attention if they develop foot ulcers.
- Fournier’s gangrene: This is a severe deep skin infection that often causes pain, swelling and/or redness around the genital area. If you develop such symptoms whilst taking these drugs, you should seek urgent medical attention as without treatment it can be fatal.
- If you suspect these important side effects are present, immediately stop the SGLT2 inhibitor and seek urgent medical attention.
How common are these serious side effects?
Diabetic ketoacidosis is estimated to occur in between 1 in 1000 and 1 in 10,000 patients treated with an SGLT-2 inhibitor. Fournier’s gangrene can occur in people who do not have diabetes but is more common in people with diabetes. It is estimated to occur in approximately 1 in 100,000 patients treated with an SGLT-2 inhibitor. This appears to be approximately 12 times more common than in patients treated with other diabetes drugs. Most cases of Fournier’s gangrene occur in men, but in patients treated with SGLT2 inhibitors it can also occur in women
What should I look out for?
The following symptoms might indicate diabetic ketoacidosis: nausea, vomiting, fast breathing, abdominal pains, unusual drowsiness, or fever.
The following symptoms might indicate Fournier’s gangrene: severe pain, tenderness, redness, or swelling in the genital or groin area accompanied by fever or generally feeling unwell.
If you have any of these symptoms, please seek help immediately, even if your blood sugars are near normal.
If we are closed, please dial 111 or 999 if you are severely unwell. Tell them that you are worried about one of the conditions above. Stop this medication until you have further medical advice.
Do I need to be monitored?
Specific monitoring after starting an SGLT2 inhibitors is not required. Unless you feel unwell, there is usually no need to have extra blood tests after starting an SGLT2 inhibitor.
You do not need to test your own blood sugars when taking an SGLT2 inhibitor unless you are also taking other diabetes medications. Your healthcare team can advise you on this.
Your medical team will continue to monitor your kidney function as part of your routine care.
Are there any sick day rules?
SGLT2 inhibitors should usually be temporarily stopped if you are more unwell than usual, including:
- Dehydration, for example through diarrhoea, vomiting, or a high temperature
- Low blood pressure, particularly if you feel dizzy or lethargic
- During admission to hospital when unwell
- Before an operation
- If you suspect ketoacidosis or Fournier’s gangrene
- If you have a urine infection or severe thrush
- If you start dialysis or undergo a kidney transplant
- If you develop active foot disease
Diuretics, (sometimes referred to as “water tablets”) and some blood pressure medications are also usually temporarily stopped if you are dehydrated or have low blood pressure.
If you usually check your blood sugar at home, it is advised you increase the number of times you check your blood sugar when unwell.
Most people can restart SGLT2 inhibitors 48 hours after a short-term illness, especially if eating and drinking fluids normally again. But you should ask your doctor, pharmacist or nurse if you are unsure, or if you think the SGLT2 inhibitor made you unwell. There are no concerns or risks associated with temporarily not taking your SGLT2 inhibitor when unwell.
What about driving?
Certain people with diabetes need to inform the Driver and Vehicle Licensing Agency (DVLA). This depends on your medication regimen, whether you hold a group 1 or group 2 licence and other individualised factors.
Full advice can be found via the DVLA website or https://www.gov.uk/diabetes-driving
If you have any queries about this medication, contact your diabetes team, GP or pharmacist.
What if I am having major surgery?
Generally you will be asked to stop this medication 24 hours before your surgery. However speak to your hospital team during your pre-operative assessment who will give you individual advice. Restart only after you are fully mobile and eating and drinking normally.