Like all medicines, pioglitazone can cause side effects, although not everyone gets them.
Common side effects
These common side effects of pioglitazone happen in more than 1 in 100 people. There are things you can do to help cope with them:
Sinus, throat or chest infections
Make sure you get your yearly flu vaccine. If you're getting a lot of infections, or you're worried, speak to your doctor.
Problems with your eyes
Your eyesight may be affected for a short time at the start of your treatment. Do not drive, cycle or use machinery until your eyesight is back to normal. If it lasts for more than a day or two, make an appointment with your doctor.
Putting on weight
Try to eat a healthy balanced diet without increasing your portion sizes. Regular exercise will also help to keep your weight stable. If you're still putting on weight see your doctor – it may be due to fluid retention.
Pins and needles (numb fingers or toes)
If pins and needles bothers you or does not go away after a few days, talk to your doctor.
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.
Serious side effects
Some people may have serious side effects after taking pioglitazone.
Call your doctor or call 111 now if:
- the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin – these can be signs of a liver problem
- you put on weight quickly, your arms, legs or stomach are swollen, and you have problems breathing – these can be signs of heart failure
- there's blood in your pee and you have problems peeing or need to pee urgently – these can be signs of bladder cancer
You're also at greater risk of breaking a bone when taking pioglitazone, particularly if you are a woman. If you're treated for a broken bone or fracture, let your doctor know as soon as possible afterwards.
Low blood sugar
Pioglitazone does not usually cause low blood sugar (known as hypoglycaemia, or "hypos") when taken on its own.
But hypos can happen when you take pioglitazone 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
- do not eat meals regularly, 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
To prevent hypos, 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 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 if 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 allergic reaction
It's possible to have a serious allergic reaction (anaphylaxis) to pioglitazone.
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.
Long-term side effects
Pioglitazone is usually safe to take for a long time. Your doctor will give you regular tests to check whether it's OK for you to continue taking it.
If you're over 65 you're slightly more likely to get some side effects of pioglitazone, such as heart failure.
Other side effects
These are not all the side effects of pioglitazone. For a full list see the leaflet inside your medicines packet.
You can report any suspected side effect using the Yellow Card safety scheme.