Like all medicines, bendroflumethiazide can cause side effects, although not everyone gets them.
You're less likely to get side effects if you're on a low dose, such as 2.5mg daily.
Side effects often get better as your body gets used to the medicine.
Common side effects of bendroflumethiazide
There are things you can do to help cope with these side effects of bendroflumethiazide:
Needing to pee more often
Try to make sure you can get to a toilet easily. Also, take it in the morning or you may need to get up in the night to use the toilet.
Speak to a pharmacist or doctor if you're finding it hard to get to the toilet in time.
Feeling thirsty, with a dry mouth
It's important not to get dehydrated, but how much you can drink will depend on why you're taking bendroflumethiazide. Check with your doctor how much water you can drink while you're taking this medicine.
Feeling or being sick (nausea or vomiting)
Stick to simple meals and do not eat rich or spicy food. If you're being sick, try frequent small sips of water to avoid dehydration. Speak to your doctor if your symptoms continue.
If you take the combined contraceptive pill or progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Diarrhoea
Drink plenty of water or other fluids. Speak to a pharmacist if you are peeing less than usual or have dark yellow and strong-smelling pee, as you could be at risk of dehydration.
Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
If you take the combined contraceptive pill or progestogen-only pill and have severe, watery diarrhoea or any diarrhoea that lasts more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Loss of appetite
Eat when you would usually expect to be hungry. If it helps, eat smaller meals but more often than usual. Snack when you're hungry and choose nutritious snacks that are high in calories and protein, such as dried fruit and nuts.
Constipation
Get more fibre into your diet by eating fresh fruit, vegetables and cereals, and drink plenty of water. Try to exercise more regularly, for example, by going for a daily walk or run. If this does not help, talk to your pharmacist or doctor.
Severe joint pain
If you get sudden severe pain in any joint, such as your big toe, wrists, elbows or knees and the skin over the joint is hot, swollen and red, this could be a sign of gout. The redness may be less noticeable on brown or black skin.
Speak to your doctor if you have these symptoms.
Feeling dizzy and faint
These could be signs of low blood pressure (hypotension).
If you feel dizzy or faint, stop what you're doing. Try sitting or lying down until you feel better, and then get up slowly. A drink of water may also help. Do not drive, ride a bike or operate machinery if you are affected.
Speak to your doctor if this keeps happening.
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
It happens rarely, but some people have a serious side effect after taking bendroflumethiazide.
Call your doctor or call 111 straight away if:
- you have bruising or bleeding (including nosebleeds) that you cannot explain, sore throat, or frequent infections – these could be a sign of blood problems
- you have severe pain in the tummy, a high temperature and feel sick or start being sick (vomiting) – these could be signs of an inflamed pancreas (pancreatitis)
- the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin, and dark pee or pale poo – these could be signs of liver problems
- you are itching a lot – this could be a sign of liver problems
- you or your child feel unusually tired, lightheaded or dizzy, or have dark yellow pee, or are peeing less than normal – these could be signs of dehydration
- you have unexpected weight loss, frequent thrush, bladder or skin infections, tiredness, blurred vision and feel more thirsty than usual
Serious allergic reaction
It's possible to have a serious allergic reaction (anaphylaxis) to bendroflumethiazide.
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.
Do not drive yourself to A&E.
The person you speak to at 999 will give you advice about what to do.
Other side effects
These are not all the side effects of bendroflumethiazide. For a full list, see the leaflet inside your medicine packet.
Reporting side effects
You can report any suspected side effect using the Yellow Card safety scheme.
Visit the Yellow Card website for more information about reporting side effects.