- High Blood Pressure Slideshow Pictures
- Take the Salt Quiz!
- Lowering Blood Pressure Exercise Tips Pictures
- What is furosemide, and how does it work (mechanism of action)?
- Is furosemide available as a generic drug?
- Do I need a prescription for this drug?
- Lasix side effects and adverse effects
- What is the dosage for furosemide?
- Which drugs or supplements interact with furosemide?
- Is this drug safe to take if I'm pregnant or breastfeeding?
- What else should I know about this medicine?
What is furosemide, and how does it work (mechanism of action)?
Furosemide is a potent diuretic (water pill) that is used to eliminate water and salt from the body. In the kidneys, salt (composed of sodium and chloride), water, and other small molecules normally are filtered out of the blood and into the tubules of the kidney. The filtered fluid ultimately becomes urine. Most of the sodium, chloride and water that is filtered out of the blood is reabsorbed into the blood before the filtered fluid becomes urine and is eliminated from the body. Furosemide works by blocking the absorption of sodium, chloride, and water from the filtered fluid in the kidney tubules, causing a profound increase in the output of urine (diuresis). The onset of action after oral administration is within one hour, and the diuresis lasts about 6-8 hours. The onset of action after injection is five minutes and the duration of diuresis is two hours. The diuretic effect of furosemide can cause depletion of sodium, chloride, body water and other minerals. Therefore, careful medical supervision is necessary during treatment. The FDA approved furosemide in July 1982.
Lasix side effects and adverse effects
Common side effects of furosemide are:
- low blood pressure,
- dehydration and
- electrolyte depletion (for example, sodium, potassium).
Other important side effects include:
- jaundice,
- ringing in the ears (tinnitus),
- sensitivity to light (photophobia),
- rash,
- pancreatitis,
- nausea,
- diarrhea,
- abdominal pain, and
- dizziness.
Increased blood sugar and uric acid levels also may occur.
What is the dosage for furosemide?
The usual starting oral dose for treatment of edema in adults is 20-80 mg as a single dose. The same dose or an increased dose may be administered 6-8 hours later. Doses may be increased 20-40 mg every 6-8 hours until the desired effect occurs. The effective dose may be administered once or twice daily. Some patients may require 600 mg daily.
The starting oral dose for children is 2 mg/kg. The starting dose may be increased by 1-2 mg/kg every 6 hours until the desired effect is achieved. Doses greater than 6 mg/kg are not recommended.
The recommended dose for treating hypertension is 40 mg twice daily. The dose of other blood pressure medications should be reduced by half when furosemide is added.
Which drugs or supplements interact with furosemide?
Administration of furosemide with aminoglycoside antibiotics (for example, gentamicin) or ethacrynic acid (Edecrin, another diuretic) may cause hearing damage. Furosemide competes with aspirin for elimination in the urine by the kidneys. Concomitant use of furosemide and aspirin may, therefore, lead to high blood levels of aspirin and aspirin toxicity. Furosemide also may reduce excretion of lithium (Eskalith, Lithobid) by the kidneys, causing increased blood levels of lithium and possible side effects from lithium. Sucralfate (Carafate) reduces the action of furosemide by binding furosemide in the intestine and preventing its absorption into the body. Ingestion of furosemide and sucralfate should be separated by two hours.
When combined with other antihypertensive drugs there is an increased risk of low blood pressure or reduced kidney function.
Nonsteroidal anti-inflammatory drugs (for example., ibuprofen, indomethacin [Indocin, Indocin-SR]) may interfere with the blood pressure reducing effect of furosemide.
Is this drug safe to take if I'm pregnant or breastfeeding?
Furosemide is secreted in breast milk. Nursing mothers should avoid breastfeeding while taking furosemide.
What else should I know about this medicine?
What preparations of furosemide are available?
Tablets: 20, 40 and 80 mg. Oral solution: 10 mg/ml and 8 mg/ml. Injection: 10 mg/ml
How should I keep furosemide stored?
Furosemide should be stored at room temperature in a light resistant container.
Summary
Lasix is the brand name for the generic drug furosemide. Lasix is a diuretic medicine that doctors prescribe to treat excess accumulation of fluid or swelling of the body (edema) caused by:
- Cirrhosis
- Chronic kidney failure
- Heart failure
- Nephrotic syndrome.
Doctors also prescribe Lasix in conjunction with other high blood pressure pills
to patients to treat high blood pressure (hypertension).
Profound
diuresis with water and electrolyte depletion can occur if Lasix drug is given
in excess amounts. Other side effects and adverse effects of this medicine
include:
- Gut (gastrointestinal or GI) reactions like pancreatitis, jaundice, anorexia, cramping, diarrhea, constipation , nausea, and vomiting.
- Systemic hypersensitivity reactions like severe anaphylactic shock, necrotizing angiitis, and interstitial nephritis.
- CNS (central nervous system) reactions like vertigo, headaches, blurred vision, tinnitus, and hearing loss.
- Blood reactions like anemia, leukopenia, thrombocytopenia, and eosinophilia.
- Hypersensitive skin reactions like rash, itching, hives, photosensitivity, exfoliative dermatitis, and Steven-Johnson syndrome.
- Heart reactions like orthostatic hypotension (fainting or dizziness when standing up) and an increase in triglyceride and cholesterol levels
Other reactions include weakness, muscle spasms, thrombophlebitis, fever, and hyperglycemia (high blood sugar). Furosemide is available as tablets of 20 mg to 80 mg, and IV form. Your doctor will determine your dosage based on your medical condition. This medication interacts with certain with drugs like cisplatin (Platinol-AQ)), cyclosporine, lithium (Eskalith, Lithobid), methotrexate (Rheumtrex, Trexall), phenytoin, antibiotics, heart and blood pressure medications, laxatives, steroids, and salicylates like aspirin. Tell your doctor or other health care professional about any vitamins or supplements you are taking. Researchers don't know if Lasix harms the fetus so talk with your doctor if you are pregnant or planning to get pregnant. This drug can be passed on to your newborn while breastfeeding and may harm your baby. It also may slow breast milk production so talk with your doctor before breastfeeding.
Multimedia: Slideshows, Images & Quizzes
-
High Blood Pressure (Hypertension) Quiz: Symptoms, Signs & Causes
Take this quiz and test your IQ of high blood pressure (hypertension), the cardiovascular disease that causes most strokes and...
-
Kidney Disease Quiz: Test Your Medical IQ
Kidney disease is common. Take this kidney disease quiz to test your knowledge and learn the symptoms, causes and types of kidney...
Related Disease Conditions
-
Cirrhosis (Liver)
Cirrhosis of the liver refers to a disease in which normal liver cells are replaced by scar tissue caused by alcohol and viral...
-
12 Congestive Heart Failure Symptoms, Stages, Causes, and Life Expectancy
Congestive heart failure (CHF) refers to a condition in which the heart loses the ability to function properly. Heart disease,...
-
Superior Vena Cava Syndrome
Superior vena cava syndrome is compression of the superior vena cava vein located in the upper chest. Causes of superior vena...
-
Kidney Failure (Symptoms, Signs, Stages, Causes, Treatment, and Life Expectancy)
Kidney failure can occur from an acute event or a chronic condition or disease. Prerenal kidney failure is caused by blood loss,...
-
Edema (Pitting)
Edema is the swelling of tissues as a result of excess water accumulation. Peripheral edema occurs in the feet and legs. There...
-
Primary Biliary Cirrhosis Treatment (PBC)
Primary biliary sclerosis (PBC) is thought to be an autoimmune disorder that involves the deterioration of the liver's small bile...
-
Hypertensive Kidney Disease
High blood pressure can damage the kidneys and is one of the leading causes of kidney failure (end-stage renal kidney disease)....
-
Heart Failure
Heart failure (congestive) is caused by many conditions including coronary artery disease, heart attack, cardiomyopathy, and...
-
High Blood Pressure Treatment (Natural Home Remedies, Diet, Medications)
High blood pressure (hypertension) means high pressure (tension) in the arteries. Treatment for high blood pressure include...
-
Low Potassium (Hypokalemia)
Potassium is an essential electrolyte necessary for cell function. Low potassium (hypokalemia) may be caused by diarrhea,...
-
Febrile Seizures
Febrile seizures, or convulsions caused by fever, can be frightening in small children or infants. However, in general, febrile...
-
Pulmonary Edema
Pulmonary edema (swelling or fluid in the lungs) can either be caused by cardiogenic causes (congestive heart failure, heart...
-
Ascites
Ascites, the accumulation of fluid in the abdominal cavity is most commonly caused by cirrhosis of the liver. Some of the other...
-
Bladder Spasms
People who have bladder spasms, the sensation occurs suddenly and often severely. A spasm itself is the sudden, involuntary...
Treatment & Diagnosis
- High Blood Pressure FAQs
- Kidney Disease FAQs
- Medication Disposal
- Dangers of Mixing Medications
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
- hydrochlorothiazide (Microzide, Hydrodiuril, Ezide, and Hydro-Par have been discontinued)
- triamterene and hydrochlorothiazide
- Drugs: Questions to Ask Your Doctor or Pharmacist about Your Drugs
- Drug Interactions
- torsemide (Demadex)
- High Blood Pressure Drugs (Hypertension)
- Congestive Heart Failure Medications
Prevention & Wellness
Quick GuideHow to Lower Blood Pressure: Exercise Tips

Health Solutions From Our Sponsors

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.