Canagliflozin is a type of medication you might need to take if you have type 2 diabetes.
- What is canagliflozin?
- How does canagliflozin work?
- How do you take canagliflozin?
- Who can take canagliflozin?
- Your prescription
- Side effects of canagliflozin
- More information and support
What is canagliflozin?
Canagliflozin belongs to the drug class SGLT2 inhibitors. There are several SGLT2 inhibitors available in the UK. Canagliflozin has the brand name Invokana.
This medication is used to manage blood sugar levels. You can take it on its own or with other diabetes medications such as metformin, sulphonylureas or insulin.
There is another medication that has both canagliflozin and metformin in one tablet, which has the brand name Vokanamet.
How does canagliflozin work?
Canagliflozin lowers blood sugar levels as it helps the kidneys to remove excess glucose or sugar, which is passed out through your urine.
This drug can also slow down the progression of kidney failure.
How do I take canagliflozin?
Canagliflozin is a tablet that you take once a day. You should take it with a drink of water and swallow it whole.
You can take it at any time of the day, but it is recommended to take it at the same time each day. You can take it with or without food.
If you take Vokanamet, which has both canagliflozin and metformin in one tablet, you should take this with food.
Always take this medication exactly as your healthcare professional has told you. The Patient Information Leaflet inside the box will tell you how to take it but always check with a healthcare professional if you are not sure.
Who can take canagliflozin?
Adults over the age of 18 years with type 2 diabetes can take canagliflozin.
Your healthcare professional may prescribe you canagliflozin if metformin is not suitable for you, and if you have chronic heart failure or heart disease, or you are at high risk of developing heart failure or heart disease.
Who can’t take canagliflozin?
Some medications might not be suitable for some people, which might be because of medical conditions or other reasons:
- Your doctor will tell you to stop taking canagliflozin if you develop diabetic ketoacidosis, or DKA;
- If you have kidney disease you might not be able to take canagliflozin or your doses might need to be reduced - this will depend on the stage of your kidney disease;
- If you have severe liver disease you might not be able to take canagliflozin;
- You might need to temporarily stop taking this medication if you’re going to have an operation;
- Canagliflozin should not be used if you are pregnant of breastfeeding. If you’re planning a pregnancy speak with a healthcare professional if you are using this medication.
When you start a new medication always check with your healthcare team that it’s suitable for you to take.
Your prescription
Your healthcare team should explain your prescription to you but it's important to make sure you ask if you don't feel you know enough.
And make sure you talk to your GP or your diabetes team if you struggle to take your medication. They might be able to help by giving you a different dose.
In England, if you need to take any medication to manage your diabetes, your prescriptions will be free. Ask your healthcare team about a prescription exemption certificate if you don't have one, to make sure you don't get charged for your medication. Prescriptions are already free for everybody in the rest of the UK, so you shouldn't pay for your medication.
Side effects of canagliflozin
Like all medications, canagliflozin can cause side effects. But when side effects are listed as common in the Patient Information Leaflet, it doesn’t mean that everyone who takes the medication will get them.
The information about side effects is based on the likelihood of people having them. For example, if a side effect is very common then it can affect more than one in ten people, and if a side effect is very rare then it affects fewer than one in 10,000 people.
Because medicines can affect people differently, your healthcare team will speak to you about what’s best for you and discuss any side effects.
Common side effects can include:
- going for a wee more often
- genital thrush
- constipation
- feeling more thirsty than usual.
Risk of low blood sugar
Canagliflozin does not usually cause blood sugar levels to become too low, also known as hypoglycaemia or hypos, when taken on its own. However, hypos can happen when you take it with other diabetes medications such as insulin or a sulphonylurea.
Your healthcare team may advise reducing the dose of your sulphonylurea or insulin medicine when you start taking canagliflozin to reduce the risk of hypos.
Risk of high blood sugar
There have been reports of people developing DKA if they take SGLT2 inhibitors, although this is a rare side effect.
The risk of DKA is higher if:
- you have had DKA before
- you’re unwell
- you’re having surgery
- your insulin doses are reduced too quickly
- you’re following a low carbohydrate diet or a ketogenic diet.
If you take canagliflozin and become unwell, you should temporarily stop taking it. You need to check your ketones and your blood sugars (if you've been told to do this and have the kit) and speak to your healthcare team. Taking this medication when you're not very well could increase your risk of developing DKA, so you need to know the signs and symptoms of DKA to look out for.
These are not all of the side effects. You will find a full list of known side effects in the Patient Information Leaflet. This comes in the medication box.
It’s also important that you take individual advice from your healthcare team before starting treatment and report any side effects to your healthcare professional, if you experience any.
You can also report these side effects to the Yellow Card Scheme, which is the government system used for recording side effects with medicines in the UK.
More information and support
Still have more questions? Or is there anything you're not sure about after reading this page? Contact our helpline on 0345 123 2399.
You can visit the NHS website for more information.
