The NHS has issued guidance urging certain individuals to consult their general practitioner before starting a widely-prescribed blood pressure medication. This particular drug, used by patients of all ages, was prescribed approximately 11 million times in 2024 alone.

Furosemide, a diuretic, aids in managing high blood pressure by eliminating surplus fluid and salt from the body. Often considered a secondary treatment option, it is typically prescribed when first-line medications like thiazide are insufficient. However, the NHS recommends that eight specific groups of people discuss the suitability of this drug with their doctors to confirm its safety for them.

According to the Mirror, individuals showing signs of dehydration, among others, should seek medical advice before using furosemide. Additionally, the NHS advises those scheduled for a glucose test, a procedure involving iodine-based dye injection, or undergoing major surgery to consult their healthcare provider.

1. Anyone who has ever had an allergic reaction to furosemide or any other medicine
2. Anyone experiencing low blood pressure (hypotension)
3. Anyone displaying signs of dehydration, such as being thirsty, having a dry mouth and dark pee
4. Anyone diagnosed with liver disease
5. Anyone diagnosed with diabetes
6. Anyone who struggles to urinate
7. Anyone diagnosed with Addison’s disease, a rare disorder of the adrenal glands
8. Anyone diagnosed with gout

The NHS explains on its website: “Diuretics are commonly referred to as ‘water tablets’ because they increase urine production, helping to expel excess fluid from the body.”

“Furosemide is accessible solely through prescription. It is available in tablet and liquid forms for oral consumption. In certain cases, it can also be administered via injection, though this is typically reserved for hospital settings.”

“Furosemide is only available on prescription. It comes as tablets and a liquid that you swallow. It can also be given by injection, but this is usually only done in hospital.”

People taking furosemide should also be mindful when combining it with other medications. According to the NHS, anyone prescribed the drug should speak with their doctor before taking the following:

• Painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs), including diclofenac, ibuprofen or naproxen
• Medicines that can change the level of potassium in your blood, such as potassium supplements, steroids, or other diuretics
• Medicines to treat, or which have the side effect of, an irregular heartbeat, including amiodarone, digoxin, disopyramide, flecainide or sotalol
• Soluble paracetamol
• Soluable co-codamol
• Certain remedies for heartburn and indigestion
• Medicines used to treat mental health problems, such as amisulpride, lithium, pimozide or risperidone
• Medicines that treat high blood pressure, or those that have a side effect of low blood pressure
• A medicine used to treat ulcers, called sucralfate, leave about two hours between the time you take furosemide and sucralfate

The NHS adds: “Tell your doctor if you are taking any potassium supplements. These change the levels of potassium in your blood and can affect the way furosemide works.

“There’s not enough information to say that other herbal remedies or supplements are safe to take with furosemide. They’re not tested in the same way as pharmacy and prescription medicines. They’re generally not tested for the effect they have on other medicines.”