Furosemide (patient information)

Why this medication is prescribed

Furosemide, a 'water pill,' is used to reduce the swelling and fluid retention caused by various medical problems, including heart or liver disease. It is also used to treat high blood pressure. It causes the kidneys to get rid of unneeded water and salt from the body into the urine.

This medicine is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How this medication should be used

Furosemide comes as a tablet and liquid to take by mouth. It usually is taken once a day in the morning or twice a day in the morning and afternoon. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take furosemide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Furosemide controls high blood pressure but does not cure it. Continue to take furosemide even if you feel well. Do not stop taking furosemide without talking to your doctor.

Special precautions

Before taking furosemide:

• tell your doctor and pharmacist if you are allergic to furosemide, sulfa drugs, or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially other medications for high blood pressure, aspirin, corticosteroids (e.g., prednisone), digoxin (Lanoxin), indomethacin (Indocin), lithium (Eskalith, Lithobid), medications for diabetes, probenecid (Benemid), and vitamins. If you also are taking cholestyramine or colestipol, take it at least 1 hour after taking furosemide.
• tell your doctor if you have or have ever had diabetes, gout, or kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. Do not breast-feed while taking this medicine. If you become pregnant while taking furosemide, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking furosemide.
• plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Furosemide may make your skin sensitive to sunlight.

Special dietary instructions

Follow your doctor's directions. They may include a daily exercise program and a low-sodium or low-salt diet, potassium supplements, and increased amounts of potassium-rich foods (e.g., bananas, prunes, raisins, and orange juice) in your diet.

What to do if you forget a dose

Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Side Effects

Minor Side Effects

Frequent urination may last for up to 6 hours after a dose and should decrease after you take furosemide for a few weeks. Tell your doctor if any of these symptoms are severe or do not go away:

• muscle cramps
• weakness
• dizziness
• confusion
• thirst
• upset stomach
• vomiting
• blurred vision
• headache
• restlessness
• constipation

Severe Side Effects

If you have any of the following symptoms, call your doctor immediately:

• fever
• sore throat
• ringing in the ears
• unusual bleeding or bruising
• loss of hearing
• severe rash with peeling skin
• difficulty breathing or swallowing
• rapid, excessive weight loss

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

Storage conditions needed for this medication

Keep this medicine in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away unused furosemide liquid after 60 days. Throw away any medicine that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medicine.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Other information

Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly, and blood tests should be done occasionally.

Do not let anyone else take your medicine. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Lasix®