Like all medicines, sitagliptin can cause side effects in some people. But many people have no side effects, or only minor ones.
Common side effects
The most common side effect of sitagliptin, which happens in more than 1 in 100 people, is headaches.
Talk to your doctor if headaches last longer than a week or are severe.
If taking sitagliptin gives you a headache, make sure you rest and drink plenty of fluids. Do not drink too much alcohol.
Ask your pharmacist to recommend a painkiller.
Low blood sugar
Sitagliptin does not usually cause low blood sugar (known as hypoglycaemia, or "hypos") when taken on its own.
But hypos can happen when you take sitagliptin with other diabetes medicines, such as insulin or gliclazide.
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 of some types of diabetes medicines
- eat meals irregularly or skip meals
- are 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.
If you're planning to exercise more than usual, make sure you eat carbohydrates like bread, pasta or cereals before, during or after exercise.
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
It happens rarely, but some people may have serious side effects after taking sitagliptin.
Call your doctor or call 111 straight away if:
- you get severe stomach pains – this may be a sign of pancreatitis
- the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin – this can be a sign of liver problems
Serious allergic reaction
It's possible to have a serious allergic reaction (anaphylaxis) to sitagliptin.
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 sitagliptin. For a full list, see the leaflet inside your medicines packet.
You can report any suspected side effect using the Yellow Card safety scheme.