Health Centres - Froop (furosemide)
How does it work?
Froop tablets contain the active ingredient furosemide (previously known as frusemide in the UK), which is a type of medicine called a loop diuretic. (NB. Furosemide is also available without a brand name, ie as the generic medicine.)
Diuretics are sometimes referred to as water tablets. They remove excess fluid from the body by increasing the production of urine.
Loop diuretics work by causing the kidneys to increase the amount of salts such as potassium and sodium that are filtered out of the blood and into the urine. When these salts are filtered out of the blood by the kidneys, water is also drawn alongside. As diuretics increase the removal of salts from the blood, they also cause more water to be drawn out of the blood and into the urine.
Furosemide is used to treat conditions where excess fluid has been retained in the body (oedema). For example, in heart failure, the pumping mechanism of the heart is less effective. This can cause fluid to build up in the ankles and the lungs (pulmonary oedema), which makes it difficult to breathe. Furosemide helps the body to remove this excess fluid. Removing fluid from the blood vessels also decreases the pressure within the blood vessels. This makes it easier for a weak heart to pump blood around the body. Furosemide is therefore used to relieve the symptoms of heart failure.
Furosemide is also used to remove excess fluid that can accumulate in people with cirrhosis of the liver. This fluid may accumulate in the abdomen (ascites) or in the legs (peripheral oedema).
Problems with blood circulation in the legs can also cause fluid retention and swelling of the ankles or lower legs, and this can also be treated with furosemide.
At higher doses the amount of water drawn from the blood into the urine is much greater, therefore furosemide is also used when there is reduced production of urine in people with kidney failure.
As furosemide decreases the pressure within the blood vessels, it is also sometimes used to treat high blood pressure, usually in people resistant to other blood pressure lowering medicines.
What is it used for?
- Removing excess fluid (oedema) from the body, for example due to conditions affecting the heart (eg heart failure), lungs, liver (eg cirrhosis), kidneys (eg kidney failure), or blood vessels.
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High blood pressure.
Warning!
- While taking this medicine you will need to have regular blood tests to monitor your kidney function and the levels of salts such as potassium and sodium in your blood.
- If you experience any of the following symptoms while taking this medicine you should inform your doctor promptly, so that the amount of fluids and salts in your body can be checked: thirst, lethargy, confusion, weakness, drowsiness, muscle cramps, scanty production of urine, abnormal heart rhythm, seizures, nausea and vomiting.
Use with caution in
- Elderly people.
- Decreased kidney function.
- Decreased liver function.
- People who have difficulty passing urine (urinary retention).
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Enlarged prostate gland .
- Low blood pressure (hypotension).
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Diabetes.
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Gout.
- Kidney failure in people with liver failure (hepatorenal syndrome).
- Low amounts of protein in the blood (hypoprotinaemia), eg due to kidney disorders.
- Premature babies.
Not to be used in
- Low volume of circulating blood (hypovolaemia).
- Dehydration.
- People who are not producing any urine.
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Kidney failure causing no urine to be produced (anuria).
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Kidney failure caused by poisoning with liver or kidney damaging agents.
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Kidney failure in people unconscious due to end-stage liver disease (hepatic coma).
- People who are losing consciousness due to liver disease affecting the brain (hepatic encephalopathy).
- Very low blood potassium levels (hypokalaemia).
- Very low blood sodium levels (hyponatraemia).
- Allergy to medicines from the sulphonamide group, eg the antibiotic sulfamethoxazole.
- Breastfeeding.
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- This medicine should be used with caution during pregnancy, and only if the expected benefit to the mother is greater than any possible risk to the foetus. Seek medical advice from your doctor.
- This medicine passes into breast milk and may also reduce the production of breast milk. Women who need treatment with this medicine should not breastfeed. Seek further medical advice from your doctor.
Side effects
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
- Nausea.
- Feeling of being unwell (malaise).
- Stomach upset.
- Headache.
- Muscle cramps.
- Low blood pressure (hypotension).
- Decreased levels of sodium, potassium, magnesium or calcium in the blood.
- Increased blood sugar levels.
- Increased blood uric acid level (hyperuricaemia) which can cause kidney problems and gout.
- Skin rashes.
- Abnormal reaction of the skin to light, usually a rash (photosensitivity).
- Hearing disorders.
- Decrease in the normal numbers of blood cells in the blood.
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.

