Frusemide is known as furosemide in the United States, and commonly by the trade name Lasix. It is a loop diuretic that acts in the kidneys to increases the production of urine. As a medication it is used in tablet or injection form to treat excess fluid in the body, high blood pressure, and heart failure causing a build up of fluid in lungs.
It should only be used in pregnancy if medically essential. It will reduce production of breast milk, and may be used to assist in drying of breast milk in women who have stopped breastfeeding. It is safe in children and infants.
Frusemide should be used with caution in diabetes, diarrhoea and gout, and regular blood tests to assess levels of chemicals (electrolytes) in blood are recommended. Do not take if suffering from severe kidney failure, liver failure, jaundice, low blood pressure, difficulty in passing urine, or low potassium or salt levels. Potassium supplements may be needed.
Passing increased amounts of urine is an obvious side effect, while others related to overuse include weakness, dizziness, thirst, muscle cramps, flushing and dehydration, blood clots. Frusemide interacts with digoxin, aspirin, steroids, salicylates, lithium, antibiotics, ethacrynic acid, NSAID, sucralfate and medications that lower blood pressure (eg. ACE inhibitors). The herbs celery, dandelion and uva ursi can also interact with it.
Its use in competitive sports is illegal as it can act as masking agent for other illegal drugs.
Frusemide is a widely used, safe, and extremely effective medication that has been available since the 1960s.