Like all medicines, dapagliflozin can cause side effects, although not everyone gets them. Side effects often improve as your body gets used to the medicine.
Common side effects
These common side effects of dapagliflozin happen in more than 1 in 100 people. They're usually mild and do not last long. There are things you can do to help cope with them:
Thrush
Ask your pharmacist to recommend an antifungal treatment for thrush. If this does not work within a week or you keep getting thrush, speak to your doctor. There are also things you can do to prevent thrush returning.
Back pain
If you get sudden unexpected back pain, do not try to treat it yourself. Contact your doctor – it might be a sign of a urinary tract infection (UTI).
Peeing more than normal
This is a sign that you're peeing out more sugar in your urine. If this side effect bothers you, talk to your doctor or pharmacist.
Feeling dizzy
Stop what you're doing and sit or lie down until you feel better. Do not drive, ride a bike or use tools or machines if you feel dizzy or shaky.
Mild skin rash
It may help to take an antihistamine. Check with a pharmacist to see what type is suitable for you. Speak to your doctor if the rash does not go away, or gets worse.
Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.
Low blood sugar
If you take dapagliflozin with other diabetes medicines, including insulin or sulfonylureas like gliclazide, your blood sugar can sometimes go too low. This is called hypoglycaemia or a "hypo".
Early warning signs of low blood sugar include:
- feeling hungry
- trembling or shaking
- sweating
- confusion
- difficulty concentrating
It's also possible for your blood sugar to go too low while you're asleep. If this happens, it can make you feel sweaty, tired and confused when you wake up.
Low blood sugar can happen if you:
- take more than your prescribed dose of some types of diabetes medicines
- skip meals, have them at unusual times or you're fasting
- do not eat a healthy diet and are not getting enough nutrients
- change what you eat
- increase your physical activity without eating more to compensate
- drink alcohol, especially after skipping a meal
- take some other medicines or herbal remedies at the same time
- have a hormone disorder, such as an underactive thyroid (hypothyroidism)
- have kidney or liver problems
It's important to have regular meals, including breakfast, to prevent hypoglycaemia. Never miss or delay a meal.
Always carry a fast-acting carbohydrate with you, like sugar cubes, fruit juice or some sweets, in case your blood sugar level gets low. Artificial sweeteners will not help.
You may also need to eat a starchy carbohydrate, like a sandwich or a biscuit, to maintain your blood sugar for longer.
If taking in sugar does not help or the hypo symptoms come back, contact your doctor or the nearest hospital.
Make sure your friends and family know about your diabetes and the symptoms of low blood sugar levels so they can recognise a hypo if it happens.
Serious side effects
Diabetic ketoacidosis (DKA)
DKA is what happens when your body starts to run low on insulin and harmful substances, called ketones, build up in the body. Signs of DKA can include:
- feeling or being sick
- feeing very thirsty
- feeling confused or unusually tired
- having stomach pain
- breath that smells fruity (like pear drop sweets, or nail varnish)
- breathing more deeply or faster
Symptoms usually develop over 24 hours, but can come on faster. Your doctor will show you how to monitor your ketone and blood sugar levels, and what to do if this happens. You'll learn how to recognise the symptoms of DKA and what to do about it.
Other serious side effects
Apart from DKA for people with type 2 diabetes, serious side effects of dapagliflozin are rare and happen in less than 1 in 10,000 people.
If you have type 2 diabetes, you will get an alert card. This is to show any health professionals involved in your care.
Call your doctor or call 111 now if:
- you have a very dry or sticky mouth, feel very thirsty, sleepy or tired, are not peeing (or peeing very little), and have a fast heartbeat – these can be signs of dehydration
- you have a high temperature or feel cold and shivery, get a burning feeling when peeing, have pain in your back or side, or blood in your urine – these can be signs of a urinary tract infection (UTI)
- you get severe pain, tenderness, redness, or swelling in the groin or perineal area accompanied by a high temperature or feeling unwell – this may be a sign of a serious infection called Fournier's gangrene
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to dapagliflozin.
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Other side effects
These are not all the side effects of dapagliflozin. For a full list, see the leaflet inside your medicines packet.
You can report any suspected side effect using the Yellow Card safety scheme.