Furosemide is a “loop” diuretic, meaning that it affects a special part of the kidney called the loop of Henle to facilitate salt elimination from the body along with extra fluid. This “water pill” not only kicks sodium out of the body (considered a beneficial action), it also promotes removal of other key minerals such as magnesium, potassium and calcium (an undesired consequence).


Q. As part of the medications I take for high blood pressure, I take Lasix two times per day, 40 mg each.
I am concerned as I just read that Lasix can potentially cause kidney damage or gout when taken over a period of time. I am very concerned that I have never been told about these serious side effects from my doctor. Are they true?

Q. My Husband’s doctor is concerned about his blood pressure. It has been fine until three days ago when at the doctor’s office it was 140/80. (When we got home it was 125/75). The doctor doubled his dose of furosemide.
I frankly am afraid he is going to end up in the hospital! I would like to learn more about this drug. My husband fortunately works close to home; he sometimes urinates on himself because he can’t always make it to the bathroom in time. He does operate heavy equipment at times and the dizziness thing is scary too. Please tell us more about furosemide.

I take prescribed 20 mg Lasix twice a day. One doctor says to take potassium with it, but another doctor says no. I don’t know what to do.

Q. My wife (54 years old) started furosemide 20 mg twice a day for fluid retention. It has helped with that, but has caused hearing loss in both ears. She has been told to stop for two weeks and see her doctor for blood work afterwards

Q. I have a very good friend who suffers from serious heart problems. He had a pacemaker implanted many years ago. That was replaced with a defibrillator pacemaker. He has been taking many medications for his heart problems, including furosemide (Lasix). He was diagnosed with diabetes about three years ago.
A few months ago, he was taken to the ER when he became very short of breath. They ran many tests and one doctor switched him from Lasix to torsemide (Demadex). Ever since this change, his blood sugar has been completely normal. Is diabetes a side effect of Lasix?


As you can see from the questions above, this diuretic is associated with a number of complications. Because it is a water pill (eliminates fluid from the body), it can cause numerous trips to the bathroom. As one reader reported above, it led to incontinence for her husband at work. Others complain that they have to get up numerous times a night to pee. More serious is dizziness. The same wife who worried that her husband had “accidents” at work also mentioned that he handled heavy equipment. The dizziness brought on by Lasix is very troublesome for someone in such a situation.
We also worry about depletion of potassium and magnesium. These electrolytes are essential for muscle function. When they are depleted from the body, muscle cramps are not an uncommon complication. Irregular heart rhythms can also occur and this can be a life-threatening situation if not corrected. Anyone on furosemide must have regular blood tests to make sure electrolytes don’t get out of whack. In some cases potassium and magnesium supplements are necessary, but they require medical supervision and close monitoring to make sure the levels are like Goldilocks and the porridge (not too hot or too cold…too much or too little).
Other concerns mentioned above include hearing loss, gout and diabetes. These complications are all linked to Lasix.
Here are some other side effects to be alert for:

• Weakness, muscle cramps (linked to electrolyte depletion)
• Dehydration
• Irregular heart rhythms (contact an MD immediately)
• Dizziness, low blood pressure, especially when standing suddenly
• Ringing in ears, hearing loss (contact an MD immediately)
• Blood problems (contact a physician if bruising or anemia occurs)
• Blurred vision
• Skin rash, itching (potentially life threatening, contact an MD immediately!)
• Elevated uric acid levels, gout
• Elevated blood sugar, diabetes
• Increases in cholesterol levels and triglycerides
• Kidney damage

No one should ever stop furosemide suddenly without medical supervision. This drug is essential for certain heart patients, especially those with congestive heart failure. Keeping excess fluid under control is critical for such patients. But furosemide is a tricky drug and requires very close monitoring by an attentive health care provider. The drug can also interact dangerously with dozens of other medications, so the pharmacist must check any other medicine that is taken to make sure there are no incompatibilities.


We have received a number of complaints that not all generic furosemide is created equal. We are especially worried about this problem for people with heart failure. If their medicine is not working as anticipated, it can lead to fluid accumulation and serious complications. We fear that the FDA has not been as vigilant about monitoring generic drugs as most health professionals think. Here are just a few stories for your consideration. If you suspect that your generic furosemide is not working as intended, let your physician and pharmacist know that this is a problem other people have encountered.

“I have mild congestive heart failure and real bad edema, with my left leg especially. I take 80 mg Lasix twice a day. The brand name works quite well. Some of the generic furosemide seems to work but it seems to have a wide range of effectiveness from manufacturer to manufacturer.
“The generic furosemide that my mail order pharmacy sends me seems to do little or nothing. I may as well be taking chalk tablets. On this stuff I retained so much water that I would gain about 15-20 lbs or more and have shortness of breath. My legs would swell up badly. I have to keep a Lasix prescription at the local pharmacy and pay for it out of my own pocket to avoid problems.”

“I take furosemide, 20 mg tablets, and for a long time took Mylan brand generic. Then the pharmacy switched me to brand XXX generic. I immediately began ‘drowning,’ and my weight jumped 5 lbs overnight. I fortunately had some Mylan brand still on hand, switched back, lost the water, and three days later tried the brand XXX again. Same result. I am on an assigned Medicare Part D Plan, and as a result the Mylan has to be special-ordered and approved for me to get it.
“These are both generic forms of the same drug, but even among generics there are big differences. A major concern is that while I recognized the problem and took immediate action (and then tested the problem out again), there are a lot of elderly people on furosemide, for instance, who would not understand this type of problem with the pill. They could end up seriously ill, with their doctors blaming them for ‘non-compliance’ problems: “Mrs. D is not taking her furosemide as directed,” when in fact it was the drug manufacturer at fault.”

Share your story about furosemide (Lasix) below. Has it worked well for you? Have you experienced any side effects? Have you had any problems with generic formulations?Others may benefit from your comments.

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    Been on furosemide 40 mg 3 times about 6 weeks and because it transformed me into a zombie, my MD dropped the dose t0 20 mg 3 times a week. Within another month my legs were so weak, I couldn’t walk at all. Waiting to hear from my cardiologist for advice.

  2. Richie S.
    Lebanon tn.

    I have been on furosemide close to 2 years. I take 160 mg a day to get excess water from my body and keep the swelling down in my legs. I manage to keep the swelling reasonably under controlA little swelling in late afternoon but down over night. I also have a kidney problem which is most likely the main reason for the high dose of furosemide. My legs are doing better and better each day, specially if I keep moving. Oh – I am 76 years old. Now I am having wetting problems and diapered 24/7. Next week I’m seeing a urologist docter but I think I prefer the diapers then more pills and tests. I feel great and can do most things except walk great distance. I have a heart – lung COPD) Kidney and anemia doctors and for the most part they agree with me

  3. Chuck

    I take Furosemide 40mg 3x daily and STILL have swollen legs, but more in the left leg. I’ve been on this for almost 4 years, I sleep with my feet elevated, and when I first wake for the day, that’s the ONLY time my lower legs and feet look and feel normal. I need to check on a different diuretic since it’s obviously not doing it’s job, except it’s robbing my body of potassium and everything else I take since I pee it all right back out of my body before it has a chance to do their jobs.

    I just and FINALLY got my Dr’s to prescribe me a potassium supplement after yet another ER visit and found to be hypokalemic yet again. MANY of the symptoms I’ve mentioned to my Dr. links directly back to a lack of potassium, so I advise anybody taking ANY diuretic, to have your blood checked OFTEN, not every 6 months like MY Dr. wants to do and thinks is fine. Do I need another Dr? You bet! But I live in a rural area and there just aren’t many choices, and on a fixed income I can’t afford to move closer to a town/city with more Dr’s to choose from.

    Educate yourself as much as possible and you may have to confront your Dr once in a while, because in spite of all the “degrees and diplomas” on the walls, they don’t know it all and sometimes just treat you like you’re part of an assembly line. Also, get to know your pharmacist, since they know more about meds than your Dr does. Luckily I’ve got a great couple of pharmacists, and I rely on them a lot. Take advantage of their knowledge, and most of the time they won’t mind sharing it with you at all. It could make a huge difference. They’ve helped me several times questioning my Dr about meds, and I was put on something else, or the existing prescription changed because it was too little or too much….like the potassium issue. On the paperwork from the hospital it CLEARLY states that any patient on furosemide is required to be on a potassium supplement. Now that I am, and still eating a healthy diet, I feel better than I have in 4 years. I feel alive again, instead of just existing.

  4. MIchael
    South Florida

    Lasix has been a God-send for me. I just worry about my fellow heart-failure patients who don’t understand the importance of being tough on themselves about a low sodium diet, in ADDITION to taking their Lasix as prescribed. The Lasix is not a “remedy” that you take so you can still have Chinese food every Sunday night. It must work in conjunction with your careful diet if it’s going to help you. Unfortunately, heart-failure is a progressive illness.

    However, if you’re diligent about your diet, and consistent with your dosage of Lasix, the progression of heart-failure CAN be slowed. I’m the proof. Get a great low-sodium cookbook and take care of yourself! The happiest benefit to come from my illness is that I’ve become a really great cook, and the kitchen has become my refuge! Cooking makes me happy, happy makes me healthy. I send best regards and good health to all who may read this. :)

  5. Shuger
    Kalkaska, MI

    I was on Lasix for years due to swelling legs…..I was allergic to the prilasec and no one seems to be aware of this. After establishing that I did not have heart problems and off the prilasec a few years, I went off the Lasix. The hair loss I was experiencing has stopped and my thoughts are a lot more clear. They (Dr.s) wanted me on anxiety drugs ect…..I feel so much better. I just can’t believe the difference. Also the swelling in my legs has gone down to about half of what they were On the drug.

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