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Lasix Oral Precautions and Side Effects


IMPORTANT NOTE: The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate or effective for you. Consult your healthcare professional before using this drug.

Table of Contents

Generic Name: FUROSEMIDE SOLUTION- ORAL
Pronounced: (fyou-ROW-seh-mide)

Lasix Oral Warning

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.

Lasix Oral Side Effects

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
  • weakness
  • unusual tiredness
  • confusion
  • severe dizziness
  • fainting
  • drowsiness
  • unusual dry mouth/thirst
  • nausea
  • vomiting
  • fast/irregular heartbeat
  • unusual decrease in the amount of urine


Tell your doctor right away if any of these unlikely but serious side effects occur:

  • 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:

  • rash
  • 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.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Lasix Oral Precautions

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
  • gout
  • lupus


If you have diabetes, furosemide may affect your blood sugar level. Check your blood sugar level regularly as directed and share the results with your doctor. Your doctor may need to adjust your diabetes medication 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. Avoid prolonged sun exposure, tanning booths, and sunlamps. Use a sunscreen and wear protective clothing when outdoors.

This drug may make you dizzy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Limit alcoholic beverages.

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).

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. Consult your doctor before breast-feeding.


CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to 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.
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