The National Health Service has issued important guidance for the millions of Britons prescribed a common medication for high blood pressure and heart failure. The advice centres on the risk of dehydration and crucial interactions patients must be aware of.
Key Risks and Who Must Consult a GP
Furosemide is one of the 20 most prescribed drugs in the UK, with around 11 million dispensations recorded in 2024. As a diuretic, often termed a "water tablet," it helps the body remove excess fluid.
The NHS stresses that anyone experiencing signs of dehydration while on this medication must contact a doctor immediately. Key warning signs include feeling unusually thirsty, having a persistently dry mouth, or passing urine that is dark in colour.
Several specific patient groups are strongly advised to speak with their GP before taking furosemide. This includes people diagnosed with liver disease, diabetes, or gout. The advice also extends to individuals who have difficulty urinating and those with Addison's disease.
Patients must inform their doctor if they have ever had an allergic reaction to furosemide or any other medicine. Furthermore, a medical consultation is essential if the patient already suffers from low blood pressure, known as hypotension.
Critical Drug and Test Interactions
Users are reminded to tell any healthcare professional if they are scheduled for specific medical procedures. This includes glucose tests, major operations requiring a general anaesthetic, and scans that involve iodine-based dyes.
A significant part of the NHS guidance covers common drug interactions. Furosemide can interact with widely used over-the-counter painkillers such as ibuprofen, naproxen, and soluble paracetamol. Certain remedies for heartburn and indigestion can also alter how effectively the diuretic works.
The medication's effectiveness may be reduced, or side effects increased, when taken alongside prescriptions for mental health conditions like lithium or risperidone. Medicines for irregular heartbeats and other high blood pressure drugs can compound the risk of blood pressure falling to dangerously low levels.
Herbal Remedies and Supplements Warning
The NHS provides a clear warning regarding complementary medicines. There is currently insufficient information to guarantee the safety of taking herbal remedies alongside furosemide.
Patients are urged to specifically disclose the use of potassium supplements to their doctor or pharmacist, as these can significantly alter the drug's effectiveness and pose health risks.
This comprehensive advice underscores the importance of open communication between patients and healthcare providers to ensure the safe use of this widely prescribed medication.
