Furosemide

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

Furosemide works by increasing the amount of urine the body makes, which helps reduce swelling and symptoms of fluid retention and helps lower high blood pressure. Furosemide tablets are sometimes called water pills as they increase how much you urinate.

Furosemide is also known as frusemide in some countries. It has been available in the United States since the 1960s and comes as tablets (Lasix), an oral liquid, an intravenous solution, and subcutaneous injections and infusions that can be given at home (Furoscix, Lasix ONYU).

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

Furosemide oral tablets and liquid are taken by mouth. Measure liquid medicine with the supplied measuring device, not a kitchen spoon.

Furosemide injection is given in a muscle, under the skin, or in a vein. A healthcare provider will give you this injection if you are unable to take the medicine by mouth.

Using subcutaneous furosemide at home

You or your caregiver should be trained before your first dose, and you should read the Instructions for Use that comes with your prescription. Wash your hands first, and check that the liquid is clear and colorless to slightly yellow. Do not use it if you see particles or if it is cloudy or discolored.

Subcutaneous furosemide is given into the abdomen only, and you should use a different spot on the abdomen each time.

Furoscix ReadyFlow autoinjector

• Choose a site at least two inches from your belly button, avoiding skin that is broken or irritated and any scars or stretch marks. Clean it and let it dry.
• Pull the blue cap straight off, then press the device firmly against your skin and hold it there for about 10 seconds, until the yellow plunger rod stops moving and fills the viewing window.
• If you lift the device away before the window is completely yellow, you may not get the full dose. Call your healthcare provider if this happens, and do not use a second device unless you are told to.

Furoscix On-Body Infusor and Lasix ONYU Infusor

• The infusion takes about 5 hours, so plan to stay somewhere you can relax and reach a bathroom.
• Apply the device to a flat, clean, hairless area of the abdomen below the rib cage and above the belt line, and press it firmly into place. Do not remove and reapply it.
• Limit your activity while wearing it and avoid bending as much as you can. Do not exercise or do anything that might knock it off.
• Do not get the infusor wet. Do not bathe, shower, or swim while wearing it, and do not apply lotions or creams to the area where it is placed.
• Traveling by car or airplane while wearing the infusor is not recommended, and the Furoscix On-Body Infusor cannot be used in an MRI setting.
• Do not use the infusor within 12 inches of mobile phones, tablets, computers, or wireless accessories such as a remote control or Bluetooth device.
• Your healthcare provider will show you what the indicator light and alarms mean. You must use the infusor in a setting where you can detect and respond to these alarms to ensure you receive the full dose. If the device falls off, or the light blinks red, call your healthcare provider and do not reuse it.

Dispose of used autoinjectors, infusors, and cartridges in a sharps container. Do not put them in household trash and do not recycle them.

General furosemide dosing information

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.

This medicine 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 furosemide 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 furosemide.

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

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

Before using this medicine, 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 this medicine even if you feel fine. High blood pressure often has no symptoms.

Furosemide is a potent diuretic which, if given in excessive amounts, can lead to a profound diuresis with water and electrolyte depletion. Careful medical supervision is required, and the dose schedule must be adjusted to the individual patient's needs.

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

You should not use furosemide if you are allergic to it or are unable to urinate.

To make sure furosemide 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
• 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.

Subcutaneous furosemide given at home

Two brands of furosemide are designed to be given under the skin at home rather than in hospital.

Furoscix is used to treat edema in adults with chronic heart failure or chronic kidney disease, including the nephrotic syndrome, and in children weighing 43 kg (94.7 lb) or more. It comes in two forms:

• the Furoscix ReadyFlow, a prefilled autoinjector that delivers 80 mg of furosemide in about 10 seconds. It can be used in adults and in children weighing 43 kg or more.
• the Furoscix On-Body Infusor, a wearable device that delivers 30 mg of furosemide over the first hour and then 12.5 mg per hour for the next 4 hours, giving 80 mg over about 5 hours. It can be used in adults and in children weighing 43 kg or more.

Do not use the Furoscix On-Body Infusor if you are allergic to medical adhesives. The Furoscix ReadyFlow contains benzyl alcohol as a preservative.

Lasix ONYU is a pre-programmed infusor containing furosemide that is FDA-approved for the treatment of edema in adults with chronic heart failure.

Subcutaneous furosemide is not for use in an emergency, and it is not for long-term use. It should be replaced with oral diuretics as soon as practical.

Pregnancy

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

Breastfeeding

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

Common side effects

Common furosemide side effects may include:

• diarrhea, constipation, loss of appetite
• numbness or tingling
• headache, dizziness
• blurred vision
• redness, bruising, swelling, or pain where a subcutaneous dose is given.

Serious furosemide side effects

Get emergency medical help if you have signs of an allergic reaction to furosemide (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).

Furosemide may cause other 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, with increased thirst, increased urination, dry mouth, or fruity breath odor
• kidney problems, with swelling, urinating less, feeling tired or short of breath
• signs of liver or pancreas problems, such as loss of appetite, upper stomach pain that may spread to your back, nausea or vomiting, dark urine, or jaundice (yellowing of the skin or eyes)
• signs of an electrolyte imbalance, such as increased thirst or urination, constipation, muscle weakness, leg cramps, numbness or tingling, feeling jittery, or fluttering in your chest.

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 the FDA at 1-800-FDA-1088.

Usual adult dose for edema associated with congestive heart failure, cirrhosis of the liver, and chronic renal disease (including nephrotic syndrome)

Oral: initial dose 20 to 80 mg orally once. This may be repeated at the same dose or increased 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 (for example, 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, careful clinical observation and laboratory monitoring are particularly advisable.

Usual Furoscix adult and pediatric 43 kg and above dose (ReadyFlow autoinjector)

• 80 mg of furosemide given subcutaneously in about 10 seconds.

Usual Furoscix adult and pediatric 43 kg and above dose (On-Body Infusor)

• 30 mg of furosemide over the first hour, then 12.5 mg per hour for the subsequent 4 hours. This dose is delivered automatically by the On-Body Infusor.
• In children weighing at least 43 kg, the device must be applied by a healthcare provider or adult caregiver.

Furoscix is not for chronic use and should be replaced with oral diuretics as soon as practical. People with significantly reduced kidney function may need additional diuretic therapy, because both Furoscix devices deliver a fixed 80 mg dose.

Usual adult furosemide dose for pulmonary edema

IV: 40 mg IV slowly over 1 to 2 minutes. If a satisfactory response does not occur within one hour, this may be increased to 80 mg IV slowly over 1 to 2 minutes.

Use: adjunctive therapy in acute pulmonary edema. IV administration is indicated when a rapid onset of diuresis is desired.

Usual adult furosemide dose for hypertension

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.

Usual pediatric furosemide oral dose for edema

Initial dose: 2 mg/kg orally once. If the diuretic response to the initial dose is not satisfactory, this may be increased by 1 or 2 mg/kg, given no sooner than 6 to 8 hours after the previous dose. Doses greater than 6 mg/kg body weight are not recommended.

Maintenance dose: adjust to the minimum effective dose.

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.

Furosemide 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 furosemide.

Drinking alcohol with this medicine can cause side effects.

Furosemide 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.

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 furosemide dose 2 hours before or 2 hours after you take sucralfate.

Tell your doctor about all your other medicines, especially:

• another diuretic (do not use furosemide with ethacrynic acid)
• methotrexate
• chloral hydrate
• lithium
• phenytoin
• an antibiotic, especially a cephalosporin or an aminoglycoside (avoid using aminoglycosides with furosemide)
• cancer medicine, such as cisplatin
• cyclosporine
• thyroid hormones
• heart or blood pressure medicine, including ACE inhibitors and angiotensin receptor blockers
• NSAIDs (nonsteroidal anti-inflammatory drugs), such as 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.

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