Bumetanide

Fluid retention and oedema are common consequences of conditions such as heart failure, kidney disease, and liver cirrhosis, and can cause significant discomfort and breathlessness when left untreated. Bumetanide tablets are a prescription loop diuretic used to remove excess fluid from the body by increasing urine production. Bumetanide is used in the management of oedema associated with heart failure, kidney disease, and hepatic conditions, and is a potent and fast-acting alternative to furosemide in the loop diuretic class. Regular monitoring of kidney function and electrolytes is an essential part of safe treatment. A prescription can only be issued following a clinical consultation with a registered prescriber.

Bumetanide tablets are an oral prescription medicine containing bumetanide as the active ingredient. Bumetanide belongs to the loop diuretic class of medicines, so called because they act on the loop of Henle in the kidney. Loop diuretics are sometimes referred to informally as water tablets. They are among the most potent diuretics available and are used to manage significant fluid overload.

Bumetanide is licensed in the United Kingdom for the treatment of oedema associated with heart failure, renal disease, and hepatic disease. It is available in two strengths: 1mg and 5mg tablets. Bumetanide is approximately 40 times more potent by weight than furosemide, meaning that 1mg of bumetanide produces a diuretic effect broadly equivalent to 40mg of furosemide. This is an important clinical consideration when switching between loop diuretics, and any such change must be managed by a prescriber.

All clinical information on this page is drawn from the current UK Summary of Product Characteristics for bumetanide tablets.

Important: Bumetanide requires regular monitoring of kidney function, electrolytes (particularly potassium and sodium), and fluid balance during treatment. Because of its potency, fluid and electrolyte losses can occur rapidly, particularly at higher doses or in patients who are already dehydrated. Your prescriber will determine the appropriate monitoring schedule for you. Online prescribing of bumetanide is only appropriate where an adequate clinical history is available and where regular monitoring can be ensured.

Bumetanide works by acting directly on the kidneys to markedly increase urine production, thereby reducing excess fluid throughout the body.

Action on the Loop of Henle

Inside the kidney, filtered fluid passes through a structure called the loop of Henle. In the thick ascending limb of this loop, sodium, potassium, and chloride are normally reabsorbed back into the body via a co-transporter protein. Bumetanide blocks this sodium-potassium-chloride co-transporter. By preventing reabsorption, bumetanide causes large amounts of sodium, potassium, and chloride to remain in the urine. Water follows these electrolytes, resulting in a marked and rapid increase in urine output.

Effect on Fluid Retention and Oedema

The removal of excess sodium and water reduces fluid accumulation in the tissues and the bloodstream. In heart failure, this relieves swelling in the legs and ankles, reduces breathlessness caused by fluid in the lungs (pulmonary oedema), and decreases the workload on the heart. In kidney and liver disease, bumetanide removes fluid that has accumulated as a result of impaired fluid regulation. Because bumetanide acts quickly and powerfully, it is important to take it exactly as prescribed and to attend all monitoring appointments.

Always take bumetanide exactly as your prescriber instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before starting treatment.

• Take bumetanide once or twice daily as directed by your prescriber. If you take it once daily, take it in the morning. If you take it twice daily, take the second dose no later than early afternoon. Taking bumetanide late in the day significantly increases the likelihood of needing to pass urine during the night.
• Bumetanide can be taken with or without food.
• Swallow the tablet whole with a glass of water.
• If you miss a dose, take it as soon as you remember on the same day. If you only remember the following day, skip the missed dose and continue with your normal schedule. Do not take two doses on the same day.
• Do not stop taking bumetanide without speaking to your prescriber first. Stopping suddenly can cause fluid to accumulate rapidly, which may worsen breathlessness, swelling, and other symptoms.
• Attend all blood test and monitoring appointments arranged by your prescriber. Bumetanide affects potassium, sodium, and kidney function, and these need to be reviewed regularly throughout treatment.

Bumetanide acts quickly and causes a significant increase in urination for several hours after each dose. Plan your daily activities with this in mind, particularly when starting treatment or after a dose increase.

Bumetanide tablets are available in two strengths through this service. The appropriate dose will be determined by your prescriber based on the condition being treated, your kidney function, your response to treatment, and any other medicines you are taking.

Bumetanide 1mg Tablets

The 1mg tablet is the standard dose used for most adults with oedema. For mild to moderate fluid retention, 1mg once daily in the morning is typically sufficient. In some patients, 1mg twice daily may be required, with the second dose taken in early afternoon. Bumetanide 1mg is broadly equivalent in diuretic effect to furosemide 40mg, though individual response may vary. Your prescriber will advise on the most appropriate dose for your circumstances.

Bumetanide 5mg Tablets

The 5mg tablet is used in patients with more severe fluid retention, or in those who have not achieved adequate diuresis on lower doses. Higher doses of bumetanide carry a greater risk of electrolyte disturbance and dehydration, and require close monitoring of kidney function and electrolytes. Doses above 5mg daily are generally used only under specialist supervision. All dosing decisions are made by your prescriber. Do not increase your dose without medical advice.

Like all medicines, bumetanide can cause side effects, although not everyone experiences them. The information below is based on the current UK SmPC. Refer to the Patient Information Leaflet for the full list.

Common Side Effects (may affect up to 1 in 10 people)

• Increased frequency of urination, particularly in the first few hours after taking the tablet. This is the intended effect of the medicine.
• Low potassium levels (hypokalaemia), which can cause muscle cramps, weakness, tiredness, and an irregular heartbeat. Regular blood tests help to detect and manage this.
• Low sodium levels (hyponatraemia), which may cause fatigue, confusion, headache, or nausea.
• Dizziness or lightheadedness, particularly when standing up quickly (postural hypotension).
• Thirst and dry mouth due to fluid loss.
• Raised blood uric acid levels, which may trigger or worsen gout in susceptible patients.

Uncommon Side Effects (may affect up to 1 in 100 people)

• Nausea, vomiting, or stomach discomfort.
• Raised blood glucose levels, which may be relevant for patients with or at risk of diabetes.
• Muscle cramps or pain.
• Skin rash or itching.
• Low magnesium levels (hypomagnesaemia), which can cause muscle weakness, tremor, and heart rhythm changes.

Serious Side Effects: Seek Urgent Medical Attention

Contact your prescriber or go to your nearest accident and emergency department promptly if you experience any of the following:

• Severe muscle weakness, significant cramps, or an irregular heartbeat, which may indicate a serious drop in potassium or other electrolytes.
• Significant reduction in urine output, which may indicate worsening kidney function or excessive dehydration.
• Signs of severe dehydration such as extreme thirst, very dark urine, dizziness, and confusion.
• Signs of a serious allergic reaction such as sudden swelling of the face, lips, tongue, or throat, difficulty breathing, or a severe skin reaction.
• Sudden severe joint pain, redness, and swelling, which may indicate a gout attack.
• Hearing problems or ringing in the ears (tinnitus) - this is a rare side effect associated with loop diuretics, most commonly at high doses. Report this promptly if it occurs.

Report any suspected side effect to your prescriber, pharmacist, or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Bumetanide Tablets May Be Suitable If You:

• Are an adult with oedema associated with heart failure, kidney disease, or liver disease and have been assessed as requiring loop diuretic therapy.
• Have not achieved adequate diuresis with another loop diuretic such as furosemide, or have a clinical reason for using bumetanide specifically.
• Are already prescribed bumetanide and require a repeat prescription through an online prescribing service, with adequate recent monitoring results available.

Bumetanide Tablets Are Not Suitable If You:

• Are anuric (producing no urine) or have severe kidney failure where diuretic therapy is contraindicated.
• Have severely low potassium or sodium levels that have not been corrected.
• Are in hepatic coma or pre-coma associated with severe liver disease.
• Are severely dehydrated or have significant reduction in circulating blood volume.
• Have Addison's disease (adrenal insufficiency).
• Are pregnant - bumetanide should not be used during pregnancy as it may adversely affect the foetus. Your prescriber will assess whether it is appropriate in exceptional circumstances.
• Are breastfeeding - bumetanide may pass into breast milk.
• Have a known allergy or hypersensitivity to bumetanide, sulfonamide-derived medicines, or any excipient listed in the SmPC.
• Are under 18 years of age (this service is for adults only).

Cautions

Bumetanide should be used with particular caution in older patients, who are at greater risk of electrolyte disturbances and postural hypotension. Caution is also required in patients with diabetes mellitus, as loop diuretics can affect blood glucose levels. Patients with gout or a history of hyperuricaemia should be monitored, as bumetanide raises uric acid levels. In patients with prostate disease or urinary outflow problems, the rapid increase in urine production may cause urinary retention. Your prescriber will take all relevant factors into account during your consultation.

Important Drug Interactions

Bumetanide can interact with a number of commonly prescribed medicines. Tell your prescriber about all medicines you take, including over-the-counter products and herbal supplements. The following interactions are of particular clinical importance:

• ACE inhibitors and angiotensin receptor blockers (ARBs): combining these with bumetanide can cause a significant fall in blood pressure, particularly with the first dose. Your prescriber will manage this carefully.
• Digoxin: low potassium caused by bumetanide increases the risk of digoxin toxicity. Electrolyte monitoring is essential in patients taking both medicines.
• Lithium: bumetanide can increase lithium levels in the blood, raising the risk of lithium toxicity. Close monitoring is required.
• NSAIDs such as ibuprofen: these can reduce the diuretic effect of bumetanide and increase the risk of kidney problems. Avoid regular use of NSAIDs while taking bumetanide.
• Aminoglycoside antibiotics such as gentamicin: concurrent use with loop diuretics may increase the risk of hearing damage (ototoxicity) and kidney toxicity.
• Antidiabetic medicines: bumetanide may affect blood glucose levels, potentially requiring adjustment of antidiabetic treatment.
• Corticosteroids: concurrent use may increase potassium loss, heightening the risk of hypokalaemia.

This is not a complete list of interactions. Your prescriber will carry out a full clinical assessment, including a review of your current medicines, before any prescription is considered.

Bumetanide is a Prescription Only Medicine that requires ongoing clinical monitoring. The clinical consultation is the essential first step. A prescription will only be issued if a registered prescriber determines, based on their individual assessment of your circumstances, that bumetanide is clinically appropriate for you.

During your online consultation with Pharmacy Planet, a registered prescriber will review your clinical information. This includes your diagnosis, current fluid balance status, kidney function results, electrolyte levels, other medicines you are taking, and any other relevant medical history. Because bumetanide is a potent diuretic requiring regular monitoring, the prescriber will also assess whether adequate monitoring is in place before considering whether to issue a prescription.

Not all consultations will result in a prescription being issued. The prescriber may request recent blood test results, recommend a different dose or medicine, or suggest that a face-to-face appointment with your GP or specialist is more appropriate. This process is designed to ensure your safety.

If you are already being managed for heart failure, kidney disease, or liver disease by your GP or a hospital team, please keep them informed of all medicines you are taking, including any prescribed through online services. Safe use of bumetanide depends on coordinated care and regular clinical oversight.

• Store below 25°C.
• Store in the original packaging to protect from light and moisture.
• Keep out of the sight and reach of children.
• Do not use after the expiry date printed on the packaging.
• Do not dispose of medicines via household waste or wastewater. Return unused or out-of-date tablets to your pharmacist for safe disposal.

Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

The table below compares diuretic tablets available at Pharmacy Planet. Diuretics lower blood pressure and reduce fluid retention by increasing urine production. Different classes of diuretic work at different sites in the kidney.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.

Pharmacy Planet is a GPhC-registered pharmacy providing prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, responsible prescribing, and accurate patient information. We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service.

Our pharmacy team is available to answer questions about bumetanide, diuretic therapy, or cardiovascular and renal health more broadly. We are committed to providing clear, honest information to support you in managing your health safely and with confidence.

References

1. Electronic Medicines Compendium (eMC). Bumetanide 1mg and 5mg Tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed August 2026.
2. National Institute for Health and Care Excellence (NICE). Chronic heart failure in adults: diagnosis and management. NICE guideline NG106. https://www.nice.org.uk/guidance/ng106. Accessed August 2026.
3. Joint Formulary Committee. British National Formulary (BNF). Bumetanide. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed August 2026.
4. NHS. Bumetanide. https://www.nhs.uk/medicines/bumetanide. Accessed August 2026.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed August 2026.