What it is used for
- Fluid build-up (oedema) from heart failure, liver, or kidney disease
- Fluid in the lungs
- High blood pressure in some situations
How it works
Furosemide makes the kidneys remove a large amount of extra salt and water from the body as urine. This relieves swelling and fluid overload and reduces the strain on the heart and lungs.
How it is taken
Available as tablets, an oral liquid, and an injection given by a healthcare professional. By mouth it is often taken in the morning, and a second dose, if needed, earlier in the day so it does not disturb sleep. Take it exactly as your doctor or pharmacist directs and follow the label; blood tests are often used to monitor your salts and kidneys.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Passing much more urine
- Dizziness or light-headedness, especially on standing
- Low potassium, sodium, or other salts
- Dehydration and increased thirst
- Muscle cramps
- Raised blood sugar or uric acid in some people
Serious effects — get help
- Severe dizziness, fainting, or signs of dehydration
- Irregular or fast heartbeat, severe muscle weakness or cramps (signs of salt imbalance)
- Hearing changes or ringing in the ears
- Very little or no urine output
- Signs of a serious allergic or skin reaction
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Other blood pressure medicines (additive effect)
- Lithium (levels can rise)
- Non-steroidal anti-inflammatory drugs such as ibuprofen
- Some antibiotics that can affect hearing (e.g. certain aminoglycosides)
- Digoxin (risk from low potassium)
- Other medicines that lower potassium
Who should take care
- Tell your clinician about kidney, liver, gout, or diabetes problems
- Discuss pregnancy or breastfeeding with your doctor
- Rise slowly to reduce dizziness, especially when starting
- Report ongoing cramps, weakness, or unusual tiredness
- Follow any fluid and weight-monitoring advice you are given