Canagliflozin reduces blood sugar levels in people with type 2 diabetes. It may be prescribed on its own or with other diabetes medicines to lower blood sugar.
Remember to follow any advice you have been given about your diet and taking exercise.
Make sure you know how to recognise the symptoms of low blood sugar. These include feeling shaky or anxious, sweating, looking pale, feeling hungry, a feeling that your heart is pounding (palpitations), and feeling dizzy.
|Type of medicine||Antidiabetic medicine (an SGLT2 inhibitor)|
|Used for||Type 2 diabetes mellitus in adults over 18 years old|
|Also called||Invokana®; combination brand: Vokanamet® (canagliflozin with metformin)|
Insulin is a hormone which is made naturally in your body, in the pancreas. It helps to control the levels of sugar (glucose) in your blood. If your body does not make enough insulin to meet its needs, or if it does not use the insulin it makes effectively, this results in the condition called type 2 diabetes (diabetes mellitus).
People with diabetes need treatment to control the amount of sugar in their blood. This is because good control of blood sugar levels reduces the risk of complications later on. Some people with type 2 diabetes can control the sugar in their blood by making changes to the food they eat and by doing more exercise. For other people medicines like canagliflozin are given alongside changes in diet.
Canagliflozin works on your kidneys to increase the amount of sugar that your body removes in your urine. You may be prescribed it to take on its own, or with other antidiabetic medicines. Canagliflozin is available in combination with another antidiabetic medicine called metformin. The combination is called Vokanamet®.
Before taking canagliflozin tablets
Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking canagliflozin it is important that your doctor knows:
- If you are pregnant, trying for a baby, or breastfeeding.
- If you have any problems with the way your kidneys work or the way your liver works.
- If you have low blood pressure (hypotension).
- If you have heart or blood vessel disease or have had a stroke.
- If you have problems with repeated urine infections.
- If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
- If you have ever had an allergic reaction to a medicine.
How to take canagliflozin tablets
- Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about canagliflozin tablets and a full list of side-effects which you may experience from taking them.
- Take canagliflozin exactly as your doctor has told you to. The usual starting dose is one 100 mg tablet daily. Your dose may be increased to 300 mg once daily if you have tolerated the lower dose well.
- Swallow the tablet whole with a drink of water - it is best taken just before your first meal of the day. Try to take your dose at the same time of day each day. This will help you to remember to take it.
- If you do forget to take a dose, take it as soon as you remember as long as it is more than 12 hours before your next dose is due. If it is less than 12 hours until your next dose, skip the missed dose but remember to take your next dose when it is due. Do not take two doses together or on the same day to make up for a forgotten dose.
- If you have been prescribed a combination tablet of canagliflozin with metformin (Vokanamet® brand) you should take one tablet twice a day. Take the tablet after you have eaten a meal or with a snack, as this will reduce the chance of an upset stomach. There are several strengths of Vokanamet® tablet available - each with different amounts of canagliflozin or metformin. You will be prescribed the strength of tablet that fits with your current canagliflozin dose.
- If you forget to take a dose of Vokanamet® take it as soon as you remember, unless it is nearly time for your next dose in which case miss out the forgotten dose. Do not take two doses together to make up for a forgotten dose.
Getting the most from your treatment
- Continue to take canagliflozin regularly - treatment for diabetes is lifelong.
- It is important that you keep your regular doctor's and clinic appointments. This is so your progress can be monitored. You are likely to need regular check-ups with an eye clinic and a foot clinic as well as with your doctor and diabetes clinic.
- Your doctor will recommend that you test for sugar in your blood regularly to check that your diabetes is being controlled. Your doctor or diabetes nurse will show you how to do this.
- Because of the way canagliflozin works, testing for sugar in your urine will always show that it is present. This makes urine testing unreliable.
- If you have been given advice by your doctor about changes to your diet, stopping smoking or taking regular exercise, it is important for you to follow the advice you have been given.
- Check with your doctor before taking up any new physical exercise, as this will have an effect on your blood sugar levels and you may need to check your blood levels more regularly.
- It is important for you to take care of the skin on your lower limbs and to report any sores or signs of infection to your doctor. Taking medicines like canagliflozin may make you slightly more likely to experience sores or ulcers on your feet and legs. If an ulcer is left untreated and gets worse it may put you at risk of amputation.
- Drinking alcohol while you are on canagliflozin will affect the control of your blood sugar and can increase the risk of complications with your treatment. Ask your doctor for advice about what limits are recommended for you.
- Canagliflozin is likely to make you pass more urine. If you get unusually thirsty or feel very tired then let your doctor know as your dose may need adjusting.
- It is important that your body does not lose too much water (become dehydrated) whilst you are being treated with canagliflozin. Ask your doctor for advice on the recommended amount of fluids you should be drinking each day. Signs that you are becoming dehydrated include: dry or sticky mouth, passing little or no urine, a fast heartbeat, feeling very sleepy or confused.
- If you are a driver you should take special care, as your ability to concentrate may be affected if your diabetes is not well controlled. Make sure you know what it feels like if your blood sugar is low. This is known as hypoglycaemia, or a 'hypo'.
- The first signs of hypoglycaemia are: feeling shaky or anxious, sweating, looking pale, feeling hungry, having a feeling that your heart is pounding (palpitations), and feeling dizzy. If these happen you should eat or drink something containing sugar or have a snack straightaway. It is advisable to check your blood sugar levels before you travel on long journeys and to have a snack with you.
- Drivers in the UK may need to inform the Driver and Vehicle Licensing Agency (DVLA) if they experience an episode of severe hypoglycaemia or experience a 'hypo' whilst driving. Ask your doctor for advice. Drivers in other countries should contact the relevant vehicle licensing agency.
Can canagliflozin cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with canagliflozin. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.
|Common canagliflozin side-effects||What can I do if I experience this?|
|Symptoms of hypoglycaemia: feeling shaky or anxious, sweating, looking pale, feeling hungry, feeling that your heart is pounding (palpitations), feeling dizzy||Eat something containing sugar, such as a biscuit or a sugary drink (not diet), and follow this up with a snack such as a sandwich. Tell your doctor if you notice these symptoms|
|Urine infections, passing urine more often or feeling an urgent need to pass urine||Continue to drink plenty of water to replace the fluids you are losing. If symptoms become troublesome, speak with your doctor|
|Yeast infections of the genitals (thrush)||Ask your pharmacist to recommend a suitable treatment to relieve your symptoms. Let your doctor know if you experience repeated infections. Yeast infections can also be a sign your blood sugar level is not well controlled|
|Constipation, feeling thirsty||Try to eat a well-balanced diet and drink several glasses of water each day|
|Feeling sick (nausea)||Try to take your tablets with a meal. If troublesome, let your doctor know|
|Changes to some blood tests||Your doctor will check for this|
Important: on rare occasions, treatment with canagliflozin can raise the levels of certain chemicals, called ketones, in your blood. This can lead to a serious condition called diabetic ketoacidosis. Contact your doctor straightaway if you notice any combination of the following symptoms:
- A sweet smell to your breath, a sweet or metallic taste in your mouth or a different smell to your sweat or urine.
- Feeling sick or being sick (vomiting), tummy (abdominal) pains.
- Losing weight quickly, feeling very thirsty, breathing unusually quickly or having difficulty with breathing.
- Confusion, tiredness or sleepiness.
If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.
How to store canagliflozin tablets
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Further reading and references
Manufacturer's PIL, Invokana® 100 mg and 300 mg film-coated tablets; Janssen-Cilag Ltd, The electronic Medicines Compendium. Dated November 2017.
British National Formulary 74th Edition (Sep 2017); British Medical Association and Royal Pharmaceutical Society of Great Britain, London.