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Medications and Drugs

Brand Names: Lasix

Generic Name: furosemide (Pronunciation: fur OH se mide)

What is furosemide (Lasix)?

Furosemide is a loop diuretic (water pill) that prevents your body from absorbing too much salt, allowing the salt to instead be passed in your urine.

Furosemide treats fluid retention (edema) in people with congestive heart failure, liver disease, or a kidney disorder such as nephrotic syndrome. This medication is also used to treat high blood pressure (hypertension).

Furosemide may also be used for purposes not listed in this medication guide.

Furosemide 20 mg-GG

round, white, imprinted with GG 21

Furosemide 20 mg-IVA

round, white, imprinted with Logo 2908

Furosemide 20 mg-MYL

round, white, imprinted with M2

Furosemide 20 mg-ROX

round, white, imprinted with 54 840

Furosemide 20 mg-WAT

oval, white, imprinted with 3436, WATSON

Furosemide 40 mg-GG

round, white, imprinted with GG 201

Furosemide 40 mg-IVA

round, white, imprinted with Logo 2907

Furosemide 40 mg-MYL

round, white, imprinted with MYLAN 216, 40

Furosemide 40 mg-ROX

round, white, imprinted with 54 583

Furosemide 40 mg-WAT

round, white, imprinted with WATSON 3437

Furosemide 80 mg-GG

round, white, imprinted with GG 80

Furosemide 80 mg-MYL

round, white, imprinted with MYLAN 232, 80

Furosemide 80 mg-ROX

round, white, imprinted with 54 533

Furosemide 80 mg-WAT

round, white, imprinted with WATSON 3438

Lasix 20 mg

oval, white, imprinted with LASIX (R), HOECHST

Lasix 40 mg

round, white, imprinted with LASIX (R) 40, HOECHST

Lasix 80 mg

round, white, imprinted with LASIX (R) 80, HOECHST

What are the possible side effects of furosemide

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using furosemide and call your doctor at once if you have a serious side effect such as:

  • ringing in your ears, hearing loss;
  • feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin;
  • painful or difficult urination;
  • pale skin, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
  • feeling light-headed or short of breath, rapid heart rate, trouble concentrating;
  • nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
  • sudden numbness or weakness, especially on one side of the body;
  • skin rash, bruising, severe tingling, pain, muscle weakness;
  • dry mouth, increased thirst, drowsiness, restless feeling, confusion, nausea, vomiting, increased urination, muscle pain or weakness, uneven heart rate, fainting, or seizure (convulsions);
  • numbness or tingly feeling around your mouth, muscle tightness or contraction, overactive reflexes;
  • headache, trouble concentrating, weakness, loss of appetite, feeling unsteady, shallow breathing or breathing that stops; or
  • severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Less serious side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about furosemide (Lasix)?

Do not use this medication if you are unable to urinate.

Before using this medication, tell your doctor if you have kidney disease, enlarged prostate, urination problems, cirrhosis or other liver disease, an electrolyte imbalance, high cholesterol, gout, lupus, diabetes, or an allergy to sulfa drugs.

Tell your doctor if you have recently had an MRI (magnetic resonance imaging) or any type of scan using a radioactive dye that is injected into your veins.

Do not take more of this medication than is recommended. High doses of furosemide may cause irreversible hearing loss.

Furosemide will make you urinate more often and you may get dehydrated easily. Follow your doctor's instructions about using potassium supplements or getting enough salt and potassium in your diet.

Avoid becoming dehydrated. Avoid exposure to sunlight or tanning beds. Follow your doctor's instructions about the type and amount of liquids you should drink while you are taking furosemide.

To be sure this medication is not causing harmful effects, your blood will need to be tested often. Your kidney or liver function may also need to be tested. Visit your doctor regularly.

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.

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.

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