Common Brand Name(s): Lasix
Important: How To Use This Information
This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Furosemide is a very potent medication. Using too much of this drug can lead to serious water and salt/mineral loss. Therefore, it is important that you are closely monitored by your doctor while taking this medication. Tell your doctor right away if you become very thirsty or confused, or develop muscle cramps/weakness. See also Side Effects section.
Furosemide is used to reduce extra fluid in the body (edema) caused by conditions such as heart failure, liver disease, and kidney disease. This can lessen symptoms such as shortness of breath and swelling in your arms, legs, and abdomen.
This drug is also used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems.
Furosemide is a "water pill" (diuretic) that causes you to make more urine. This helps your body get rid of extra water and salt.
How To Use
Read the Patient Information Leaflet if available from your pharmacist before you start taking furosemide and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth as directed by your doctor, with or without food, usually once or twice daily. It is best to avoid taking this medication within 4 hours of your bedtime to prevent having to get up to urinate. Carefully measure the dose using the special measuring device/spoon that comes with your prescription. Do not use a household spoon because you may not get the correct dose.
Dosage is based on your medical condition, age, and response to treatment. For children, the dose is also based on weight. Older adults usually start with a lower dose to decrease the risk of side effects. Do not increase your dose or take it more often than directed.
Take this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time(s) of the day as directed. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick.
Sucralfate, cholestyramine, and colestipol can decrease the absorption of furosemide. If you are taking any of these drugs, separate the timing of each dose from furosemide by at least 2 hours.
Tell your doctor if your condition does not improve or if it worsens (for example, your blood pressure readings remain high or increase).
Dizziness, lightheadedness, headache, or blurred vision may occur as your body adjusts to the medication. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
This medication may cause a serious loss of body water (dehydration) and salt/minerals. Tell your doctor right away if you have any of these unlikely but serious side effects:
- muscle cramps
- unusual tiredness
- severe dizziness
- unusual dry mouth/thirst
- fast/irregular heartbeat
Tell your doctor right away if any of these unlikely but serious side effects occur:
- signs of kidney problems (such as change in the amount of urine)
- numbness/tingling/pain/redness/swelling of the arms/legs
- hearing changes (such as ringing in the ears, temporary or permanent decreased hearing/deafness)
- stomach/abdominal pain
- yellowing eyes/skin
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:
- itching/swelling (especially of the face/tongue/throat)
- severe dizziness
- trouble breathing
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking furosemide, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of:
- kidney problems
- liver problems
- inability to make urine
If you have diabetes, furosemide may affect your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
Furosemide may reduce the potassium level in your blood. Your doctor may instruct you to add potassium-rich foods to your diet (such as bananas, orange juice) or prescribe potassium supplements to prevent potassium loss. Ask your doctor for more details.
This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.
This drug may make you dizzy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Severe sweating, diarrhea, or vomiting can increase the risk of dehydration. Report prolonged diarrhea or vomiting to your doctor. Follow your doctor's instructions about the amount of fluids you can drink.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Babies born early (premature infants) and children may be more sensitive to certain effects of this drug, such as kidney stones.
Older adults may be more sensitive to the effects of this drug, especially dizziness and water/mineral loss.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
This drug passes into breast milk and may affect milk production. Consult your doctor before breast-feeding.
See also the How to Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include:
- ethacrynic acid
Some products have ingredients that could raise your blood pressure or worsen your swelling. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).
This medication may interfere with certain lab tests (such as thyroid hormone levels), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: fainting, severe weakness, a severe decrease in the amount of urine.
Do not share this medication with others.
Lifestyle changes that may help this medication work better include exercising, stopping smoking, reducing stress, and changing your diet. Consult your doctor for more details.
Laboratory and/or medical tests (such as kidney tests, blood mineral levels such as potassium) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
Check your blood pressure regularly while taking this medication. Learn how to monitor your own blood pressure at home, and share the results with your doctor.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
Store in the original container at room temperature away from light and moisture. Do not freeze or store in the bathroom. After the bottle is opened, refer to the manufacturer's instructions about when to discard this medication. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised May 2019.
Copyright(c) 2019 First Databank, Inc.
Conditions of use: The information in this database is intended to supplement, not substitute for the expertise and judgment of healthcare professionals. The information in not intend to cover all possible uses, directions, precautions, drug interactions or adverse effects nor should it be construed in indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.