Lasix (furosemide) is a loop diuretic (water pill) that prevents your body from absorbing too much salt, allowing the salt to instead be passed in your urine.
Lasix treats fluid retention (edema) in people with congestive heart failure, liver disease, or a kidney disorder such as nephrotic syndrome. This medication is also used to treat high blood pressure (hypertension).
Lasix may also be used for purposes not listed in this medication guide.
Important information about Lasix
You should not use Lasix if you are unable to urinate.
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. High doses of Lasix may cause irreversible hearing loss. If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.
Before taking Lasix
You should not use Lasix if you are unable to urinate.
To make sure you can safely take Lasix, tell your doctor if you have any of these other conditions:
- kidney disease;
- enlarged prostate, bladder obstruction or other urination problems;
- cirrhosiss or other liver disease;
- an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);
- high cholesterol or triglycerides (a type of fat in the blood);
- 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.
FDA pregnancy category C. It is not known whether Lasix will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. Furosemide can pass into breast milk and may harm a nursing baby. This medication may also slow breast milk production. Do not use Lasix without telling your doctor if you are breast-feeding a baby.
How should I take Lasix?
Take Lasix exactly as prescribed by your doctor. Do not take more of this medication than is recommended. High doses of Lasix may cause irreversible hearing loss. Follow the directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results.
Measure liquid medicine with a special dose-measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.
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.
While using Lasix, you may need blood tests at your doctor’s office. Visit your doctor regularly. If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms. Store at room temperature away from moisture, heat, and light. Lasix liquid medicine should be used within 60 to 90 days after opening the bottle. Ask your pharmacist how many days your medicine is good for. Throw away any unused liquid after that time has passed.
What happens if I miss a dose?
Lasix is sometimes used only once, so you may not be on a dosing schedule. If you are using the medication regularly, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
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, or hot and dry skin.
What should I avoid while taking Lasix?
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.
What are the possible side effects of Lasix?
Get emergency medical help if you have any of these signs of an allergic reaction to Lasix: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using Lasix and call your doctor at once if you have a serious side effect such as:
- ringing in your ears, hearing loss;
- itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
- severe pain in your upper stomach spreading to your back, nausea and vomiting;
- weight loss, body aches, numbness;
- swelling, rapid weight gain, urinating less than usual or not at all;
- chest pain, new or worsening cough with fever, trouble breathing;
- pale skin, bruising, unusual bleeding, feeling light-headed, rapid heart rate, trouble concentrating;
- low potassium (confusion, uneven heart rate, leg discomfort, muscle weakness or limp feeling);
- low calcium (tingly feeling around your mouth, muscle tightness or contraction, overactive reflexes);
- headache, feeling unsteady, weak or shallow breathing; or
- severe skin reaction — fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Less serious Lasix side effects may include:
- diarrhea, constipation, stomach pain;
- dizziness, spinning sensation; or
- mild itching or rash.
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.
What other drugs will affect Lasix?
If you take sucralfate (Carafate), take it at least 2 hours before or after you take Lasix.
Tell your doctor about all other medicines you use, especially:
- cisplatin (Platinol);
- cyclosporine (Neoral, Gengraf, Sandimmune);
- ethacrynic acid (Edecrin);
- lithium (Eskalith, Lithobid);
- methotrexate (Rheumatrex, Trexall);
- phenytoin (Dilantin);
- an antibiotic such as amikacin (Amikin), cefdinir (Omnicef), cefprozil (Cefzil), cefuroxime (Ceftin), cephalexin (Keflex), gentamicin (Garamycin), kanamycin (Kantrex), neomycin (Mycifradin, Neo Fradin, Neo Tab), streptomycin, tobramycin (Nebcin, Tobi);
- heart or blood pressure medication such as amiodarone (Cordarone, Pacerone), benazepril (Lotensin), candesartan (Atacand), eprosartan (Teveten), enalapril (Vasotec), irbesartan (Avapro, Avalide), lisinopril (Prinivil, Zestril), losartan (Cozaar, Hyzaar), olmesartan (Benicar), quinapril (Accupril), ramipril (Altace), telmisartan (Micardis), valsartan (Diovan), and others;
- a laxative (Metamucil, Milk of Magnesia, Colace, Dulcolax, Epsom salts, senna, and others)
- salicylates such as aspirin, Disalcid, Doan’s Pills, Dolobid, Salflex, Tricosal, and others; or
- steroids (prednisone and others).
This list is not complete and other drugs may interact with Lasix. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.