Experiences with
GliclazideGliclazide is used to treat type 2 diabetes.
It's a medicine known as a sulfonylurea. Sulfonylureas increase the amount of insulin your pancreas makes. This lowers your blood sugar.
Type 2 diabetes is a condition where the body does not make enough insulin, or makes insulin that does not work properly. This causes high blood sugar (hyperglycaemia).
Gliclazide is available on prescription. It comes as standard and slow-release tablets.
Who can take gliclazide
Most adults and children aged 12 and over can take gliclazide.
Who may not be able to take gliclazide
This medicine is not used to treat type 1 diabetes (when your body does not produce insulin).
Gliclazide is not suitable for some people. To make sure it's safe for you, tell your doctor before starting the medicine if you:
- have ever had an allergic reaction to gliclazide or any other medicine
- have ketone bodies and sugar in your urine (diabetic ketoacidosis)
- have severe kidney or liver disease
- have a rare condition called porphyria
- are pregnant, trying to get pregnant or breastfeeding
- have a condition called G6PD-deficiency
- need to have surgery
Dosage and strength
Doses of gliclazide can vary. Take this medicine as prescribed by your doctor.
The maximum daily dose for standard gliclazide is 320mg. If you need to take more than 160mg a day, it should be divided into 2 equal doses.
For slow-release gliclazide, the maximum daily dose is 120mg.
Changes to your dose
Your doctor will check your blood sugar levels regularly and may change your dose of gliclazide if necessary.
How to take it
Swallow your gliclazide tablets whole with a drink of water. Do not chew them.
If you are taking 2 doses a day, take 1 dose with your breakfast and 1 dose with your evening meal.
If you are taking slow-release gliclazide, take your dose once a day with breakfast.
How long to take it for
Treatment for diabetes is usually for life. Do not stop taking your gliclazide tablets without talking to your doctor. If you stop taking gliclazide suddenly, your diabetes may get worse.
Gliclazide is safe to take for a long time. There's no evidence it harms your pancreas or your general health. However, it may stop working properly after a while, so your doctor may want to stop it or add a different medicine to help keep your blood sugar level stable.
If you forget to take it
If you miss a dose of gliclazide, skip the missed dose and take the next dose at the usual time.
Do not take 2 doses to make up for a forgotten dose.
If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
If you take too much
- you take more than your prescribed dose of gliclazide – an overdose of gliclazide can cause low blood sugar
Get help from 111 online or call 111
If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.
Bring the gliclazide packet or leaflet inside it, any remaining medicine, and any other medicines you take.
Common side effects
There are things you can do to help cope with these common side effects of gliclazide:
Try to rest and relax. It can help to eat and drink slowly, and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help.
If you're in a lot of pain, speak to your pharmacist or doctor
Take your tablets with a meal. Stick to simple meals and avoid rich or spicy food.
Take small, frequent sips of water or squash to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat vomiting without speaking to a pharmacist or doctor.
If you take the combined contraceptive pill or the progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
If you take the combined contraceptive pill or the progestogen-only pill and have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Get more fibre into your diet, such as fresh fruit, vegetables and cereals, and drink plenty of water. Try to increase your level of exercise, for example by going for a daily walk or run.
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
Gliclazide can sometimes cause your blood sugar to go too low. The name for this is 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 may happen if you:
- take too much gliclazide
- eat meals irregularly or skip meals
- are fasting
- do not eat a healthy diet and are not getting enough nutrients
- change what you eat
- exercise too much without eating enough carbohydrates
- drink alcohol, especially after skipping a meal
- have a hormone disorder, such as an underactive thyroid (hypothyroidism)
- have kidney or liver problems
Preventing a hypo
To prevent having a hypo, it's important to have regular meals, including breakfast. Never miss or delay a meal.
If you're planning to exercise more than usual, make sure you eat carbohydrates like bread, pasta or cereals before, during or afterwards.
Always carry a fast-acting carbohydrate with you. If you think you have low blood sugar, try having something to eat or drink that quickly gets sugar into your bloodstream. This could be something like sugar, fruit juice, jelly babies or glucose or dextrose tablets. Artificial sweeteners will not help.
This type of sugar will not last long in your blood, so you may also need to eat a starchy carbohydrate, like a sandwich or a biscuit.
Call your doctor or contact 111 if taking in sugar does not help or the hypo symptoms come back.
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
Serious side effects are rare.
Call a doctor or call 111 straight away if:
- the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on black or brown skin – these can be signs of a liver problem
- you're paler than usual, you get prolonged bleeding, bruising, sore throat and high temperature – these can be signs of a blood disorder
Your eyesight may be affected for a short time, especially at the start of treatment, because of changes in your blood sugar levels. Do not drive, cycle or use tools or machinery until this gets better. If you are concerned and it does not go away, talk to your doctor.
Serious allergic reaction
It's possible to have a serious allergic reaction (anaphylaxis) to gliclazide.
Meds New IA (H4) - serious allergic reactionThese are not all the side effects of gliclazide. For a full list, see the leaflet inside your medicine's packet.
Gliclazide and pregnancy
Gliclazide is not recommended in pregnancy as there is little information about its safety during pregnancy.
Other medicines used to treat diabetes, such as insulin and metformin, are safe to take during pregnancy.
Talk to your doctor or pharmacist before taking gliclazide. They will need to review your treatment and may be able to suggest a different medicine for you.
Gliclazide and breastfeeding
Gliclazide is not usually recommended while breastfeeding. We do not know how much of it passes into breast milk. It's only likely to be a small amount but it could lower your baby's blood sugar level.
If you are breastfeeding, or planning to breastfeed, talk to your doctor about what's best for you and your baby. They will need to review your treatment and may be able to suggest a different medicine for you.
If your doctor says it's OK to keep breastfeeding, contact your health visitor, midwife, pharmacist or doctor as soon as possible if your baby:
- is not feeding as well as usual
- seems unusually sleepy or drowsy
- seems unusually restless or irritable
- is paler, or more sweaty, than usual
- seems hungrier than usual
- is peeing more
- is causing you any other concerns
If you do need to take gliclazide while breastfeeding, your baby's blood sugar level may need to be checked occasionally.
Gliclazide and fertility
There's no clear evidence that taking gliclazide reduces fertility in either men or women.
Speak to a pharmacist or your doctor before taking it if you're trying to get pregnant.
Meds New IA (H2) - Pregnancy non-urgent care cardCautions with other medicines
There are some medicines that affect the way gliclazide works. Taking them at the same time as gliclazide can cause low blood sugar.
Tell your doctor if you're taking any of these medicines:
- steroid tablets, such as prednisolone
- some medicines used to treat heart problems and high blood pressure
- medicines to treat bacterial or fungal infections, such as clarithromycin or fluconazole
- painkillers – non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin
- medicines used to treat asthma, such as salbutamol
- male and female hormones, such as testosterone, oestrogen or progesterone
- other diabetes medicines
- medicines that help to prevent blood clots, such as warfarin
You might need a small adjustment in your gliclazide dose after starting contraceptive pills. In rare cases, they can increase blood sugar levels.
Taking gliclazide with painkillers
It's safe to take paracetamol with gliclazide.
Talk to your pharmacist or doctor before taking NSAIDs such as aspirin or ibuprofen. These painkillers can affect gliclazide and lower your blood sugar levels too much.
Mixing gliclazide with herbal remedies and supplements
Do not take the herbal remedy St John's wort (sometimes taken for depression). It may change the way your body processes gliclazide.
There's not enough information to say that other herbal remedies and supplements are safe to take with gliclazide. However, taking them at the same time as gliclazide can cause low blood sugar.
Herbal remedies and supplements are not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
Meds New IA (H2) - Cautions with other medicines alertRelated links
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