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Common Brand Name(s): Lasix
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.
This is a very potent medication. Using too much of this drug can lead to serious water and mineral loss. It is important that you are closely monitored by your doctor. Tell your doctor right away if you become very thirsty or confused, or develop muscle cramps/weakness while taking this medication.
See also Side Effects section.
Furosemide is a "water pill" (diuretic) that increases the amount of urine you make, which causes your body to get rid of excess water. This drug is used on a short-term basis in a hospital setting. It is used to treat adults with severe kidney disease who have not responded to usual doses of furosemide.
Take this medication by mouth with or without food, as directed by your doctor. The dosage is based on your medical condition and response to therapy. Only 1 or 2 doses are usually needed to see a benefit.
Sucralfate, cholestyramine, and colestipol can decrease the absorption of furosemide. If you are taking any of these drugs, separate them from furosemide by at least 2 hours.
If your condition lasts or gets worse, contact your doctor or pharmacist.
Dizziness, lightheadedness, headache, blurred vision, loss of appetite, stomach upset, diarrhea, or constipation may occur as your body adjusts to the medication. If any of these effects last or get worse, notify 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 this medication has been prescribed because your doctor 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 lead to dehydration and electrolyte imbalance. Tell your doctor right away if you have any of these unlikely but serious symptoms of dehydration or electrolyte imbalance:
Tell your doctor right away if you have any serious side effects, including:
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:
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:
If you have diabetes, furosemide may affect your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
This drug may reduce the potassium levels in your blood. Ask your doctor about adding potassium to your diet. A potassium supplement may be prescribed by your doctor.
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 drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. 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).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Your doctor may tell you to temporarily stop treatment with this medication before certain medical, surgical, or dental procedures.
Older adults may be more sensitive to the side effects of this drug, especially dizziness and water/mineral loss.
During pregnancy, furosemide 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:
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. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center.
Do not share this medication with others.
Lab and/or medical tests (such as kidney function, blood mineral levels such as sodium/potassium) should be done while you are using this medication. Consult your doctor for more details.
Have your blood pressure checked regularly while taking this medication. Discuss with your doctor how to monitor your own blood pressure.
If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.
If you have questions about missing a dose or you don't have more medication, contact your healthcare provider or pharmacist.
Store at room temperature away from light and moisture. Do not store in the bathroom. 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 February 2023.
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