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Generic Name: Furosemide
Brand Name(s):
Information updated: April 1, 2000
Overview
Furosemide, sometimes prescribed under the brand name Lasix, is a potent
diuretic, or water pill.
It is used to treat high blood pressure as well
as a number of serious conditions in which fluid builds up in body tissues
Side Effects and Interactions
People on furosemide may feel dizzy or faint if
they stand up rapidly.
Older people especially may need to take care to
avoid falling when they first get up.
Increased frequency of urination
is common but may be less bothersome if you take your medicine at breakfast
rather than at night.
Other adverse reactions to be alert for include
rash, itching, sensitivity to sunlight leading to sunburn, ringing in the ears,
nausea, diarrhea or constipation, muscle cramps, hearing loss, unexplained sore
throat with fever, bruising, blurred vision, loss of appetite, increases in
blood sugar, headache, gout and tingling or numbness in hands or feet.
Report any symptoms to your physician promptly.
Furosemide can
interact with a number of other medications. Lanoxin
and other digitalis heart medicines may cause abnormal heart rhythms if
potassium levels are decreased by diuretics.
Indocin, Clinoril, ibuprofen,
Dilantin
and activated charcoal may interfere with the effectiveness of furosemide.
At high doses, furosemide can increase the activity of the blood thinner
Coumadin.
Adding furosemide to thiazide diuretics may deplete the body rapidly of
fluid and minerals, and calls for careful monitoring.
Licorice
can greatly increase potassium loss in people taking Lasix.
Lasix and
other potassium-wasting diuretics are probably incompatible with the herb cascara sagrada, at least if it were used more than very occasionally. Cascara
sagrada, like other strong laxatives, may reduce the absorption of other
medicines taken orally.
Aloe
(latex) might be dangerous for anyone taking Lasix because of an additive
effect. It should be avoided in such situations.
Check with your doctor
and pharmacist to make sure furosemide is safe in combination with any other
drugs or herbs you take.
Special Precautions
Like many diuretics, furosemide depletes the body of potassium and other important minerals. People taking this medicine may need to include potassium-rich foods in their diet.
Vegetables such as potatoes, beets, brussels sprouts, spinach, cabbage, broccoli, carrots, peppers and squash are good sources of potassium. So are apricots, strawberries, bananas, oranges, peaches and plums.
Most fish also provide good quantities of this mineral.
Some people may not be able to maintain adequate potassium levels even with a diet rich in fish, fruits and vegetables.
Periodic blood tests are crucial to monitor potassium levels in the body. If such a test shows that potassium levels are low, your physician may recommend you cook with a potassium-based salt substitute or he may prescribe a potassium supplement.
Taking the Medicine
Furosemide is absorbed most completely when it is taken on an empty stomach.
This medication may cause stomach upset, however, which tends to be less of a problem when it is taken with food or milk. As the dose should be adjusted individually, with the help of blood tests, let your doctor know if you will change the way you take this drug.
Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio.
© 2000