Reviewed by Dr Samantha Miller MB ChB
(2017, University of Glasgow)
GMC number: 7561464
Information last reviewed 04/09/2021
Bendroflumethiazide is a type of medication called a diuretic used to treat high blood pressure (hypertension) and swelling caused by a build-up of fluid in the body (oedema).
Bendroflumethiazide gets rid of fluid and salt from the body by making you urinate more. This helps to reduce blood pressure.
Bendroflumethiazide starts working within hours. People usually need to pass urine about 2 hours after taking a dose of bendroflumethiazide, and then again a few hours later. One dose of bendroflumethiazide is effective for 12–24 hours. The full effect may take 3–4 days.
Bendroflumethiazide starts working within hours. People usually need to pass urine about 2 hours after taking a dose of bendroflumethiazide, and then again a few hours later. One dose of bendroflumethiazide is effective for 12–24 hours. The full effect may take 3–4 days.
Bendroflumethiazide tablets contain either 2.5 mg or 5 mg of the active ingredient bendroflumethiazide.
As well as bendroflumethiazide, your medication also contains inactive ingredients. These are lactose, magnesium stearate, maize starch, pregelatinised maize starch, stearic acid and water.
Please note: inactive ingredients may vary between different manufacturers of generic bendroflumethiazide.
Bendroflumethiazide is available in tablet or liquid form. Tablets should be swallowed whole with a glass of water. You can take them with or without food.
Liquid bendroflumethiazide should always be measured out using the spoon or syringe included in the packaging. Shake the bottle well before taking it.
It’s recommended to take bendroflumethiazide in the morning, and avoid taking it after 4 pm to avoid the need to pass urine overnight.
Your GP will advise you on dosage, but for treating high blood pressure, the usual dosage is one 2.5 mg tablet daily. Tablets are available in 2.5 mg and 5 mg dosages, and for oedema, you may be prescribed up to 10 mg of bendroflumethiazide per day.
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the forgotten dose and take the next one on schedule.
If you overdose on bendroflumethiazide, seek medical attention immediately.
As with all medications, some people may experience side effects when taking bendroflumethiazide. These are usually mild, and can include:
Most side effects will subside as your body adjusts to the medicine. If you are experiencing prolonged unpleasant side effects, see your GP. They may suggest reducing your dose or trying an alternative medication that may suit you better.
Serious side effects of bendroflumethiazide are rare. If you experience any of the following symptoms, seek medical help immediately.
Bendroflumethiazide is not suitable for everyone. It should not be taken if you have:
Do not take bendroflumethiazide if you are pregnant or breastfeeding.
Tell your doctor before starting bendroflumethiazide if you have any of the following:
Other drugs or medicines may interfere with the way that bendroflumethiazide works, or cause harmful symptoms. Always talk to your doctor if you are taking other prescription or non-prescription drugs, so that they can decide which treatment is safest.
In particular, be aware of the following known drug interactions with bendroflumethiazide:
This is not an exhaustive list, so always seek medical advice if you are taking other medicines or herbal remedies.
Most side effects of bendroflumethiazide are mild and can be managed effectively.
You may feel more thirsty than usual. Check with your doctor how much water you should be drinking to prevent dehydration, because depending on your condition, drinking too much liquid could be harmful.
Some people experience nausea when they take bendroflumethiazide, or they may vomit. If this happens to you, avoid rich or spicy foods, and try eating little and often. Small sips of water can also help. See your doctor if symptoms continue for more than a week.
You might have some stomach pain. If this happens, relaxing with a hot water bottle can help to mitigate the pain. Eat little and often, and see your doctor if the pain continues. Any sudden, severe pain should be checked by a doctor immediately.
If you experience diarrhoea, you may be at risk of dehydration, so keep up your fluid intake and check with your doctor how much water you should drink. Medications to treat diarrhoea may interact with bendroflumethiazide, so do not take anything without speaking to a doctor or pharmacist.
Constipation can be improved by eating plenty of fruit, vegetables and fibre-rich foods, and drinking water. Regular exercise can also help, and this doesn’t have to be strenuous – a daily walk can be enough to help your digestive system.
Some people lose their appetite when they start taking bendroflumethiazide. If this happens to you, it’s important to make sure you are receiving all the nutrients you need. Keep your mealtimes the same, but eat less if you feel like it. Make sure the meals you do eat are nutritious, and snack when you feel hungry.
Because bendroflumethiazide works to reduce your blood pressure, you may experience symptoms like dizziness and faintness, which are signs of low blood pressure. If you feel faint or dizzy, stop what you are doing, and do not drive or operate machinery. Seek medical advice if symptoms continue, as you may need to reduce your dose.
There are some side effects that cannot be managed without medical help. Joint pain can be a symptom of gout, while weight loss, skin infections, bladder infections, thrush, tiredness, blurred vision and thirst together could indicate high blood sugar. If you experience these, or any other painful or worrying symptoms, seek medical advice.
Because alcohol can affect your blood pressure, it is advisable to avoid drinking for a few days when you first start taking bendroflumethiazide. After this, you can drink in moderation (following the national guidelines on alcohol units). If you feel dizzy or dehydrated, it may be best to avoid drinking alcohol altogether.
Dizziness can be a side effect of bendroflumethiazide, so it’s sensible to wait and see how you react to the medicine before driving or operating heavy machinery. If you feel dizzy, do not drive until you feel better.
Bendroflumethiazide is not recommended for use by patients who are pregnant. That’s because the drug can reduce blood flow, cutting down the volume of blood that reaches the baby through the placenta, posing a risk to the baby’s health. Pregnant women with high blood pressure are normally prescribed alternative medicines.
Breastfeeding women are advised not to take bendroflumethiazide because it can be passed on to the baby in the mother’s milk. Bendroflumethiazide can also reduce the amount of milk produced.
No, bendroflumethiazide does not reduce the effectiveness of any form of contraception. If you have high blood pressure, however, some forms of hormonal contraception such as the pill and the patch may not be suitable for you. Talk to your GP if you have any concerns.
There are no studies linking bendroflumethiazide with a fall in fertility, although having high blood pressure can make both women and men less fertile. In some cases, however, bendroflumethiazide may affect men’s ability to get an erection. If this happens to you, talk to your GP. They may stop treatment for a few weeks to see if bendroflumethiazide is the cause.
Bendroflumethiazide is one of a class of thiazide diuretics, which are usually prescribed to treat hypertension. Other thiazide diuretics include chlortalidone, indapamide, metolazone and xipamide. These are not suitable for all patients: in particular, people with conditions including gout, Addison’s disease, kidney disease or liver disease should not be prescribed thiazide diuretics.
Two other classes of diuretics are also available: loop diuretics and potassium-sparing diuretics.
Loop diuretics include bumetanide, furosemide and torasemide. These may be more suitable than thiazide diuretics for patients with impaired kidney function.
If potassium levels are a concern, you may be prescribed a potassium-sparing diuretic such as eplerenone, spironolactone, triamterene or amiloride instead of bendroflumethiazide. This type of diuretic medicine will not cause your potassium levels to drop.
Depending on why you are taking bendroflumethiazide, there may be several alternative treatments available.
For hypertension, lifestyle changes such as cutting down salt in your diet may help to reduce your blood pressure and even avoid medication altogether. Other blood pressure medicines include:
For oedema, lifestyle changes such as staying active, reducing salt intake and elevating the affected part of the body can all help reduce your symptoms. Alternative types of diuretics can also be prescribed.
Bendroflumethiazide is a blood pressure treatment and is not prescribed to treat asthma. If you do have asthma, however, it is important to check with your GP before taking bendroflumethiazide. That’s because, like some asthma treatments, bendroflumethiazide can reduce the levels of potassium in your blood. Your GP will need to ensure that it is safe for you to take these medicines at the same time.
A diuretic (sometimes called a water tablet) is a substance or medication that makes you urinate more than usual. Bendroflumethiazide is a thiazide diuretic, which is most often used to treat high blood pressure.
Because bendroflumethiazide acts to reduce your blood pressure, it could cause dangerously low blood pressure when combined with a general anaesthetic. Talk to your surgeon before the procedure takes place. They may advise you to stop taking bendroflumethiazide 24 hours before your surgery is scheduled.
Yes, it is usually safe to take bendroflumethiazide for an extended period of months or years. However, if you are taking it long-term you should have periodic check-ups with your GP or nurse to make sure the bendroflumethiazide isn’t causing a chemical imbalance in your blood, that your kidney function is normal, and that it continues to be the best treatment for your condition.
Prices from:
We’re a fully regulated pharmacy, with qualified doctors and happy customers
Very quick and easy I had nearly run out of my prescribed blood pressure tablets an wanted a bit of a surplus just in case so was pleased
Mrs Dunmore
Quick and discreet
Straightforward & efficient service. Easy to use & gives me peace of mind. Would thoroughly recommend. Thank you.
Tony