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

Lasix is used to treat fluid retention (edema) in people with congestive heart failure, liver disease, or a kidney disorder such as nephrotic syndrome.

Lasix is also used to treat high blood pressure (hypertension).

You should not use Lasix if you are unable to urinate.

Using more than your recommended dose will not make this medicine more effective. High doses of furosemide may cause irreversible hearing loss.

Before using Lasix, 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.

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

Tell your doctor about all your other medicines. Some drugs should not be used with Lasix.

Take Lasix exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Do not use more than your recommended dose. High doses of furosemide may cause irreversible hearing loss.

Doses are based on weight in children and teenagers. Your child's dose may change if the child gains or loses weight.

Lasix 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.

Your blood pressure will need to be checked often and you may need other medical tests.

If you have high blood pressure, keep using Lasix even if you feel well. High blood pressure often has no symptoms.

If you need surgery, tell the surgeon ahead of time that you are using Lasix.

Store at room temperature away from moisture, heat, and light.

Usual Adult Dose of Lasix for Ascites:

Oral: Initial dose: 20 to 80 mg orally once; may repeat with the same dose or increase by 20 or 40 mg no sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Maintenance dose: Administer the dose that provided the desired diuretic effect once or twice a day (e.g., at 8 am and 2 pm).

Usual Adult Dose of Lasix for Congestive Heart Failure:

Oral: Initial dose: 20 to 80 mg orally once; may repeat with the same dose or increase by 20 or 40 mg no sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Maintenance dose: Administer the dose that provided the desired diuretic effect once or twice a day (e.g., at 8 am and 2 pm).

Usual Adult Dose of Lasix for Edema:

Oral: Initial dose: 20 to 80 mg orally once; may repeat with the same dose or increase by 20 or 40 mg no sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Maintenance dose: Administer the dose that provided the desired diuretic effect once or twice a day (e.g., at 8 am and 2 pm).

Usual Adult Dose of Lasix for Nephrotic Syndrome:

Oral: Initial dose: 20 to 80 mg orally once; may repeat with the same dose or increase by 20 or 40 mg no sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Maintenance dose: Administer the dose that provided the desired diuretic effect once or twice a day (e.g., at 8 am and 2 pm).

Usual Adult Dose of Lasix for Renal Failure:

Oral: Initial dose: 20 to 80 mg orally once; may repeat with the same dose or increase by 20 or 40 mg no sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Maintenance dose: Administer the dose that provided the desired diuretic effect once or twice a day (e.g., at 8 am and 2 pm).

Usual Adult Dose of Lasix for Liver Cirrhosis:

Oral: Initial dose: 20 to 80 mg orally once; may repeat with the same dose or increase by 20 or 40 mg no sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained.
Maintenance dose: Administer the dose that provided the desired diuretic effect once or twice a day (e.g., at 8 am and 2 pm).

Comments:
-Edema may be most efficiently and safely mobilized by giving this drug on 2 to 4 consecutive days each week.
-When doses greater than 80 mg/day are given for prolonged periods of time, careful clinical observation and laboratory monitoring are particularly advisable.

Usual Adult Dose of Lasix for Pulmonary Edema:

Oral: Initial dose: 80 mg/day, usually divided into 40 mg orally twice a day

Use: Treatment of hypertension alone or in combination with other antihypertensive agents.

Maximum Adult dose: 600 mg/day in patients with clinically severe edematous states.

Usual Pediatric Dose for Edema:

Oral: Initial dose: 2 mg/kg orally once; if the diuretic response to the initial dose is not satisfactory, may increase by 1 or 2 mg/kg and administer no sooner than 6 to 8 hours after the previous dose.
Maintenance dose: Adjust to minimum effective dose.

Maximum dose: 6 mg/kg

Use: Treatment of edema associated with congestive heart failure, cirrhosis of the liver and renal disease, including the nephrotic syndrome, especially when an agent with greater diuretic potential is desired.

You should not use Lasix if you are allergic to furosemide, if you are unable to urinate or have hepatic cirrhosis.

To make sure Lasix is safe for you, tell your doctor if you have ever had:

• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);

• enlarged prostate, bladder obstruction, or other urination problems;

• gout;

• lupus;

• diabetes;

• an allergy to sulfa drugs;

• kidney disease; or

• cirrhosis or other liver disease.

Tell your doctor if you have an MRI (magnetic resonance imaging) or any type of scan using a radioactive dye that is injected into a vein. Contrast dyes and furosemide can harm your kidneys.

It is not known if furosemide will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It may not be safe to breastfeed while using Lasix. Ask your doctor about any risk. Lasix may slow breast milk production.

Lasix is sometimes used only once, so you may not be on a dosing schedule. If you are using the medication regularly, use the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include feeling very thirsty or hot, heavy sweating, hot and dry skin, extreme weakness, or fainting.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Avoid becoming dehydrated. Follow your doctor's instructions about the type and amount of liquids you should drink while you are using Lasix.

Drinking alcohol with this medicine can cause side effects.

Lasix could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

If you have high blood pressure, ask a doctor or pharmacist before taking any medicines that can raise your blood pressure, such as diet pills or cough-and-cold medicine.

Get emergency medical help if you have signs of an allergic reaction to Lasix (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Lasix may cause serious side effects. Call your doctor at once if you have:

• a light-headed feeling, like you might pass out;

• ringing in your ears, hearing loss;

• muscle spasms or contractions;

• pale skin, easy bruising, unusual bleeding;

• high blood sugar - increased thirst, increased urination, dry mouth, fruity breath odor;

• kidney problems - swelling, urinating less, feeling tired or short of breath

• signs of liver or pancreas problems - loss of appetite, upper stomach pain (that may spread to your back), nausea or vomiting, dark urine, jaundice (yellowing of the skin or eyes); or

• signs of an electrolyte imbalance - increased thirst or urination, constipation, muscle weakness, leg cramps, numbness or tingling, feeling jittery, fluttering in your chest.

Common Lasix side effects may include:

• diarrhea, constipation, loss of appetite;

• numbness or tingling;

• headache, dizziness; or

• blurred vision.

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.

Sometimes it is not safe to use certain medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective

If you also take sucralfate, take your Lasix dose 2 hours before or 2 hours after you take sucralfate.

Tell your doctor about all your other medicines, especially:

• another diuretic, especially ethacrynic acid;

• methotrexate;

• chloral hydrate;

• lithium;

• phenytoin;

• an antibiotic;

• cancer medicine, such as cisplatin;

• heart or blood pressure medicine; or

• NSAIDs (nonsteroidal anti-inflammatory drugs) - aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

This list is not complete. Other drugs may interact with furosemide, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Furosemide starts working within an hour, but it could take a few weeks before you notice the full effects.

If you’re using this medicine for high blood pressure, you may not have symptoms and might not feel any different. Don’t stop taking furosemide without first talking to your doctor, even if you don’t observe any changes.

You might have to take this medicine for a long time, possibly even the rest of your life.

Your dosage of furosemide will depend on your medical condition, age, and other factors.

If you have kidney problems, your doctor may adjust the dose of furosemide.

Sometimes, doctors prescribe furosemide for other purposes, such as to ease certain symptoms in end-of-life patients who are undergoing palliative care.