Bendroflumethiazide

What is bendroflumethiazide?

Bendroflumethiazide is a thiazide diuretic (water tablet) that helps your body get rid of excess salt and water by increasing urine output. This reduces fluid build-up and lowers blood pressure[1].  

What is bendroflumethiazide used to treat?

It is primarily prescribed for[1]: 

• High blood pressure (hypertension) 

• Oedema (fluid retention), often due to heart failure or liver disease 

How does bendroflumethiazide work?

It works by[1]: 

• Increasing salt and water excretion by the kidneys 

• Reducing fluid volume in blood vessels 

• Lowering blood pressure and reduces swelling 

Who can take bendroflumethiazide?

It’s suitable for most adults but not usually recommended for people who[1]: 

• Are allergic to thiazide diuretics 

• Have severe kidney or liver problems or difficulty urinating 

• Have Addison’s disease 

• Have high levels of calcium or uric acid in your blood 

• Have diabetes, lupus, gout or low potassium, sodium, or megnesium levels 

• Are pregnant, trying to get pregnant or breastfeeding (consult a doctor) 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is the typical dose of bendroflumethiazide?

The usual dose of bendroflumethiazide tablets is [1]:  

• High blood pressure: 2.5mg taken once daily, usually in the morning 

• Fluid build-up: 5mg to 10mg once a day, which may be reduced to a single dose 1 to 3 times a week 

The dose may be adjusted by your doctor depending on your age and how well your kidneys are working. Some people are prescribed this medication twice a day, please follow the instructions on your prescription or medication label. 

How do you take bendroflumethiazide?

You can take bendroflumethiazide with or without food, just swallow whole with water at the same time each day. It is best to take it in the morning, to avoid waking in the night to urinate. If you are prescribed the medication twice a day, take one dose in the morning and one at midday[1]. 

Can you stop taking bendroflumethiazide?

Do not stop suddenly without medical advice. Stopping can cause blood pressure to rise or fluid to build up again[1]. 

What if you take too much bendroflumethiazide?

Taking too much can cause[1]: 

• Dehydration 

• Vomiting 

• Low blood pressure and dizziness 

• Electrolyte imbalance 

Seek immediate medical attention if you think you’ve taken too much. 

What if you forget a dose of bendroflumethiazide?

If you forget a dose, you should take it as soon as you remember unless it is late afternoon onwards. In this case skip the dose and take your next dose at the usual time to prevent increased urination during the night. Do not double up to make up for a missed dose[1]. 

Medicines to avoid or use with caution when taking bendroflumethiazide

Bendroflumethiazide may interact with[1]: 

• Lithium (used for bipolar disorder) 

• NSAIDs (like ibuprofen) 

• Other blood pressure medicines or diuretics 

• Steroids 

• Diabetes medications 

• Allopurinol 

• Ciclosporin 

• Anti-arrhythmics (digoxin, flecainide, sotalol, disopyramide) 

• Anti-emetics (domperidone, metoclopramide, prochlorperazine) 

• Anti-depressants (amitriptyline, citalopram, venlafaxine) 

• Carbamazepine 

• Asthma inhalers containing formoterol, salbutamol or salmeterol 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of bendroflumethiazide?

The most common side effects include[1]: 

• Increased urination 

• Dizziness or light-headedness 

• Increased thirst, nausea or vomiting 

• Diarrhoea 

• Constipation 

• Severe joint pain (this could be gout and you should speak to your doctor). 

The rarer, but more serious side effects include[1]: 

• blood disorders which may cause bruising, bleeding, sore throats, or frequent infections 

• pancreatitis which may cause severe stomach pain, temperature, and vomiting 

• liver problems which may cause yellow skin, eyes, dark pee, pale poo, or itching 

• severe dehydration which may cause lightheadedness, tiredness, dark yellow pee or reduced urination 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include:

• Difficulty breathing

• Tightness in throat and chest

• Swelling of the tongue or throat

• Feeling faint or dizzy

• Blue/grey skin or lips

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about bendroflumethiazide

How long does bendroflumethiazide take to work? 
It starts working in about 2 hours, but full effects on blood pressure may take 3-4 days[1]. 

Can I drink alcohol with bendroflumethiazide? 
Alcohol can increase the blood pressure lowering effect so the medicine and can contribute to dehydration. It is best to wait a few days to see how the medication effects you before drinking alcohol. If you have high blood pressure you should avoid drinking large amounts of alcohol regularly as this can contribute to the condition[1]. 

Can I take bendroflumethiazide long-term? 
Yes, many people take it for months or years under medical supervision[1]. 

Will I need regular tests? 
Yes, your doctor may monitor your blood pressure, kidney function, and electrolyte levels[1]. 

Can I drive on bendroflumethiazide?  
This medication may make you feel dizzy, especially when first starting the medication or on higher doses. If you are affected in this way then you should not drive, ride a bike, or operate tools or machinery[1]. 

What should I do if I am unwell whilst taking bendroflumethiazide? 
If you have diarrhoea or vomiting and cannot eat or drink properly, please speak to a doctor or pharmacist. You may need to stop taking bendroflumethiazide for a few days so that you do not become severely dehydrated or develop an acute kidney injury[1]. 

For the official NHS guide for bendroflumethiazide, visit their website.