Furosemide can cause dehydration and electrolyte imbalance. If you experience any of the following symptoms, call your doctor immediately: decreased urination; dry mouth; thirst; nausea; vomiting; weakness; drowsiness; confusion; muscle pain or cramps; or rapid or pounding heartbeats.

Furosemide injection is used to treat edema (fluid retention; excess fluid held in body tissues) caused by various medical problems, including heart failure, pulmonary edema (excess fluid in the lungs), kidney, and liver disease. Furosemide is in a class of medications called diuretics (‘water pills’). It works by causing the kidneys to get rid of unneeded water and salt from the body into the urine.

Furosemide injection comes as a solution (liquid) to be injected intramuscularly (into a muscle) or intravenously (into a vein) by a doctor or nurse in a medical office or hospital. It may be given as a single dose or it may be given once or twice a day. Your dosing schedule will depend on your condition and on how you respond to treatment.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before using furosemide injection,

• Tell your doctor and pharmacist if you are allergic to furosemide, sulfonamide medications, any other medications, or any of the ingredients in furosemide injection. Ask your pharmacist or check the patient information for a list of the ingredients.
• Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: aminoglycoside antibiotics such as amikacin, gentamicin (Garamycin), or tobramycin (Bethkis, Tobi); angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin, in Lotrel), captopril (Capoten), enalapril (Vasotec, in Vaseretic), fosinopril, lisinopril (in Prinzide, in Zestoretic), moexipril (Univasc, in Uniretic), perindopril (Aceon), quinapril (Accupril, in Accuretic), ramipril (Altace), and trandolapril (Mavik, in Tarka); angiotensin II receptor antagonists (ARB) such as azilsartan (Edarbi, Edarbyclor), candesartan (Atacand, in Atacand HCT), eprosartan (Teveten, in Teveten HCT), irbesartan (Avapro, in Avalide), losartan (Cozaar, in Hyzaar), olmesartan (Benicar, in Azor, Benicar HCT), telmisartan (Micardis, in Micardis HCT), and valsartan (Diovan, in Diovan HCT, Exforge); aspirin and other salicylates; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, Kefzol), cefditoren (Spectracef), cefepime (Maxipime), cefixime (Suprax), cefotaxime (Claforan), cefoxitin, cefpodoxime, cefprozil, ceftazidime (Fortaz, Tazicef), ceftriaxone, cefuroxime (Ceftin, Zinacef), and cephalexin (Keflex); corticosteroids such as betamethasone (Celestone), budesonide (Entocort), cortisone (Cortone), dexamethasone, fludrocortisone, hydrocortisone (Cortef), methylprednisolone (Depo-Medrol, Medrol, others), prednisolone (Prelone, others), prednisone (Rayos), and triamcinolone (Aristocort, Kenacort); corticotropin (ACTH, H.P. Acthar Gel); cisplatin (Platinol); cyclosporine (Gengraf, Neoral, Sandimmune); digoxin (Lanoxin); ethacrynic acid (Edecrin); indomethacin (Indocin); laxatives; lithium (Lithobid); medications for pain; methotrexate (Trexall); phenobarbital; phenytoin (Dilantin, Phenytek); and secobarbital (Seconal). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• Tell your doctor if you have kidney disease. Your doctor may not want you to use furosemide.
• Tell your doctor if you have or have ever had any condition that stops your bladder from emptying completely, hypertension, diabetes, gout, systemic lupus erythematosus (SLE; a chronic inflammatory condition), or liver disease.
• Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while using furosemide injection, call your doctor.
• If you are having surgery, tell the doctor that you are using furosemide injection.
• Plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Furosemide may make your skin sensitive to sunlight.
• You should know that furosemide may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position. This is more common when you first start taking furosemide. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up. Alcohol can add to these side effects.

If your doctor prescribes a low-salt or low-sodium diet, or to eat or drink increased amounts of potassium-rich foods (e.g., bananas, prunes, raisins, and orange juice) in your diet, follow these instructions carefully.

Furosemide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• Frequent urination
• Blurred vision
• Headache
• Constipation
• Diarrhea

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

• Fever
• Ringing in the ears
• Loss of hearing
• Ongoing pain that begins in the stomach area, but may spread to the back
• Rash
• Hives
• Blisters or peeling skin
• Itching
• Difficulty breathing or swallowing
• Yellowing of the skin or eyes
• Light-colored stools
• Dark urine
• Pain in the upper right part of the stomach

Furosemide may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• Extreme thirst
• Dry mouth
• Dizziness
• Confusion
• Extreme tiredness
• Vomiting
• Stomach cramps

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body’s response to furosemide.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.