Lasix (Furosemide)

Lasix or furosemide is a water tablet or loop diuretic that doesn't let salt be absorbed in your body. When a person uses this medicine, the salt just goes out through emiction.

This medicine helps people that have fluid retention or edema and at the same time they have disorder of kidney like nephritic syndrome or such diseases like liver disease or congestive failure of the heart. Doctors use this drug to medicate hypertension.

If it is not possible for a patient to urinate, he is forbidden to take Lasix.

People that take this medicine should be warned that they could have fluid excessiveness or loses of electrolyte in their body. One of the side effects can be postural hypotension but it can easily be set by a slow rising. You can control the appearing of hypokalemia by adding some potassium in your food or staying on an appropriate diet.

The tablets of Lasix are sold in 20 mg, 40 mg or 80 mg pills. Generic Lasix liquid is sold in 10mg per teaspoon of Furosemide and also in 40mg per teaspoon of Furosemide. In hospitals, sometimes they use an injectable version of generic Lasix.


High blood pressure
High blood pressure

Lasix for high blood pressure

There are two numbers in the reading of blood pressure, e.g. 120/80. Usually they put diastolic blood pressure as a bottom number and systolic blood pressure as a top number. It is considered that a person has a high blood pressure, when it is more than 140/90 and that have multiple readings of blood pressure.

When people made researches with Lasix, they developed that it can decrease greatly diastolic and systolic blood pressure. It was also discovered that some health problems can happen by decreasing blood pressure. They can be congestive heart failure, diseases of the heart or stroke after a high blood pressure that was for a long time. Still, Lasix can not be considered as a medicine against increased blood pressure.

Water retention
Water retention

Lasix for water retention

Congestive heart failure is one of the diseases that commonly occur to people that have water retention. CHF occurs when the heart is not able to pump a sufficient amount of blood through the whole area of body. This condition doesn't cause the stopping of heart beat; it just signifies that your heart doesn't have enough force to pump blood in a usual way. You can have other CHF symptoms, like swollen ankles, lower part of legs or feet and you might have briefness of breath.

Water retention can also appear to those that have liver cirrhosis or failure of kidney, called renal failure. People can use Lasix to cure water retention that was caused by these diseases.

Extra fluid will go away when Lasix will treat your organism against fluid retention. Pay attention that Lasix is not a medicine that cures CHF or other diseases that appeared due to the water retention.

Lasix use in children

Little babies and children are approved to take Lasix as a medicine against water retention, but not against high blood pressure.


General dosing information

Lasix 20mg, 40mg, 80mg
Lasix 20mg, 40mg, 80mg
Patients that receive Latex should consider the following:
  • There are pills of 20mg, 40mg and 80mg pills of Lasix. You can take the pill either one or two times a day or in some conditions you can take it several times.
  • You can divide a tablet of Lasix on two parts, if it is convenient
  • The pill can be taken during nourishing or after, there is no difference
  • You have to find a convenient time for taking a pill and try to take is at this time each day. It will help you to keep the amount of Lasix in your blood. In some conditions patients can take the medicine not every day, in particular those that have fluid retention.
  • The medicine enhances emiction, so it is better if you take it in the morning. You will escape getting up at night and going to the toilet. If you are assigned to take Lasix several times a day, you should take the last pill before 6 o'clock in the evening.
  • Patients of older age should begin to take the medicine with a lower dose, because they could have some side effects from taking Lasix.
  • The patient needs to take the medicine how it is prescribed, if he wants to get benefits from the medicine. It will not be effective if you stop the medication.
  • You should speak to your nurse or a doctor, if you are hesitating about this kind of treatment or you don't know what dose will be appropriate for you.

High blood pressure

Patients with increased blood pressure are recommended to take 40mg of Lasix two times a day. The doctor should investigate your blood pressure and how your body reacts to Lasix treatment. After that, he could set what dose you need to take. Every time the dose changes you need some weeks to observe how Lasix effects on your blood pressure by decreasing it.

Water retention

For patient with edema, the Lasix dose can differ from 20 to 600 mg per day. This dose can be taken at once or divided into several intakes. There are people that can use Lasix only when they experience the retention of water. The others should take this drug every day.

Dosing for infants and children

Kids and babies have an approval to take Lasix as a treatment against water retention. It is not approved to treat high blood pressure in babies and children. They usually prescribe a dose of 0.9 mg per pound or 2mg of medicine per kilogram at the beginning for kids and babies. If it is needed, pediatrician can rise up the dosage of medicine, up to 2,7 mg per pound or 6mg per kg.

Warnings and Precautions

Lasix precautions
Lasix precautions
When you just started to take Lasix, it is better to talk to your doctor before if you know that you have:
  • Kidney failure or kidney disease
  • Such problems with liver like cirrhosis
  • Passing urine difficulties
  • Diabetes
  • Gout
  • Electrolyte or fluid problems
  • Somatic lupus erythematosus (SLE or lupus)
  • Any kinds of allergies, including allergy to drugs, sulfa, foods, preservatives, or dyes.

Before taking Lasix your doctor also needs to know if there are some other drugs (over the counter or prescription, herbal supplements, or vitamins) that you are using at the moment.

Some warnings and precautions

In the following we give a list of warnings and precautions that you should know about Lasix:
Very low blood pressure
Very low blood pressure
  • In order to treat ascites (abdominal cavity fluid retention) or cirrhosis Lasix should be taken with precautions, preferably in the hospital so that these people could be closely monitored.
  • People allergic to "sulfa" drugs, or sulfonamides, may be Lasix allergic too.
  • Lasix can interact with some medicines.
  • Lasix can damage your kidney, therefore it is better to stop using this drug once you experienced that your kidney problems are deteriorating (especially for people with severe kidney problems).
  • Lasix can lead to very low blood pressure, especially at the beginning of medication and when its dosage changes. People on dialysis or those that have cardiac insufficiency, vomiting, diarrhea, or excessive sweating. People taking Lasix should drink fluids on a regular basis.
  • Some hearing problems may occur during taking Lasix, including permanent hearing loss in some cases. It is highly possible in case Lasix is given in high doses intravenously and when it is combined with some other medicine which can cause loss of hearing. People who have a kidney disease may be at risk too. Your doctor should be informed immediately if there are any hearing deteriorations or tinnitus (ringing in the ears).

If you notice any symptoms of lowered blood pressure (they may be lightheadedness, faintness or weakening) talk to your medical consultant. You should stop Lasix and contact a healthcare provider when you passed out. You should also not forget about how the medicine affects you prior to driving, operating heavy machinery, or performing other tasks requiring alertness. In some cases Lasix affects electrolytes levels in blood (including calcium, sodium, magnesium, potassium, and chloride); your doctor will check them regularly. It is prior to inform the doctor when you feel there are symptoms of electrolyte imbalance. The symptoms are:
Electrolyte imbalance
Electrolyte imbalance
  • Thirst
  • Decreased urination
  • Weakness
  • Lowered blood pressure, or hypotension
  • Drowsiness
  • Tachycardia (rapid heart beating), arrhythmia (irregular heart rhythms)
  • Lethargy
  • A dry mouth
  • Muscle pains or cramps
  • Restlessness
  • Vomiting or nausea

People with passing urine difficulties that could be the outcome of bladder problems or an enlarged prostate should take Lasix with precautions. Lasix can cause urinary retention, because it doesn't help with the passing urine difficulties but increases urine production.

In people with diabetes Lasix can lead to high sugar in blood (hyperglycemia), in some cases it may even bring about diabetes in those people who don't have history of the condition. In premature infants Lasix may cause calcium deposits or kidney stones. Additional monitoring is required for premature babies taking Lasix.

This medicine belongs to the medication of Category C in pregnancy. It means that it might be unsafe during pregnancy. Before taking Lasix during pregnancy consult your doctor about the risks and benefits. It is better to talk more and to ask questions to your doctor when you nourish your child with your breast milk you plan to start it, because Lasix may pass through brest milk.

Who should not take Lasix?

People allergic to Lasix in particular or to furosemide and any other inactive component of the drug. You can get a list of inactive components from your doctor.

Side Effects

In case you have symptoms of having an allergy to the medicine, you should get emergency help. The symptoms are: breathing difficulty, urticaria, your lips, face, tongue and throat swell. You should interrupt using Lasix and go to your medical care provider straightaway in case you notice some other serious symptoms: ringing in the ears or loss of hearing; severe thirst, feeling very hot, urination disorder, dry and hot skin, or heavy sweating;
Lasix side effects
Lasix side effects
  • difficulties or pains during urination;
  • pains in upper stomach, nausea, appetite loss, itching, dark urine or clay-colored stools, jaundice (skin or eyes yellowing);
  • unusually pale skin, unusual bleedings in your vagina, nose, mouth or rectum, purple or hot pink spots under the skin;
  • severe thirst, dry mouth, drowsiness, restlessness, confusion, vomiting, nausea, increased urination, pain or weakness in muscles, uneven heart rhythms, seizure (convulsions), or fainting;
  • bruises, skin rash, hard tingling, muscle weakness, pains;
  • headaches, concentrating troubles, appetite loss, weakness, unsteadiness, shallow or stopping breathing;
  • numbness, tingling around the mouth, muscle contraction or tightness, unusually active reflexes;
  • experiencing shortness of breaths or light-headed, rapid heart beating, concentrating troubles;
  • sudden one-side weakness or numbness;
  • very strong skin reactions - sore throat, fever, tongue or face swelling, eye burning, skin pain accompanied by purple or red spreading rash in the upper body or face causing peeling and blistering.

Some other side effect that are not so serious:

Mechanism of action

Lasix formula
Lasix formula
Furosemide is kind of drug that increases the flow of urine, like any other it inhibits NKCC2, the luminal transporter of Na-K-2Cl in the dense rising limb of the loop of Henle. The effect on the outside tubes doesn't rely on the prohibitive effect that is made on carbonic aldosterone or anhydrase. It blocks negative and positive clearance of water in a free way and destroys the osmotic corticcomedullar gradient.

Henle's loop has a huge capacity to absorb NaCl. It explains why the production of acidosis does not limit the diuresis like it happens sometimes to carbonic anhydrase inhibitors.

The loop diuretics through inhibiting the transporter lead to reduction of the quantity of NaCl to be absorbed once again and to the decreasen of lumen-positive potential that appears after K+ is recycled. Usually it happens that this electrical potential is putting those reabsorbed cations that have a valency of two to the loop. Such action makes this potential lower and the excretion of Mg2+ and Ca2+ is increased in the loop. If people use this medicine for a long time, some patients could get huge hypomagnesemia. After the process of reabsorption of Ca2+ to the outside coiled tube is finished, the loop diuretic could not make hypocalcemia to happen.

Another fact about furosemide is that it can noncompetitively block receptors of GABA-A in subtype specific way. It also can counteract with currents that were caused by GABA-A, especially those receptors of α6β2γ2 at a concentrations of μM, but it doesn't include receptors of α1β2γ2. When the development process is started, the receptors of α6β2γ2 raise up the expression of cerebellar granule neurons that in their turn make the sensitivity to furosemide more increased.

Normally, such electrical potential (EP) makes the reabsorption of divalent cation in the loop.

Lasix alternatives

Alternatives for people with high blood pressure

Lasix alternatives
Lasix alternatives
There are numerous Lasix alternatives to control hypertension, or high blood pressure. They are:
  • Changing your diet to that with more vegetables and fruits;
  • Additional physical exercises;
  • Losing weight;
  • Avoiding alcohol;
  • Less salt consumption;
  • Changing medication.

Alternatives for retention of water

Some Lasix alternatives to treat water retention (edema):
  • Less salt and fluid consumption.
  • Using support stockings in order to reduce water retention in the legs;
  • Changing diuretic medication;
  • More physical activity, avoiding keeping the same position (standing or sitting) for too long.

Drug interactions

Some interaction may happen if a person takes Lasix with some medicine for blood pressure, or other drugs, like lithium or digoxin. A person could experience the following side effects from this interaction: decreased levels of potassium, deafness, decreased blood pressure. A doctor who examines you should know if you take any other medicine except Lasix because you may have very strong side effects.

In the following text we give a list of other drugs with which Lasix can interact.
  • Aminoglycoside antibiotics:
    Aminoglycoside antibiotics
    Aminoglycoside antibiotics
    • Amikacin (Amikin)
    • Gentamicin
    • Kanamycin (Kantrex)
    • Neomycin (Neo-Fradin)
    • Streptomycin
    • Tobramycin
  • Other blood pressure medicines
  • Chloral hydrate
  • Corticosteroids:
    • Prednisone
    • Hydrocortisone (Cortef)
    • Dexamethasone (Decadron, Dexone, Hexadrol)
  • Cyclosporine (Gengraf, Neoral, Sandimmune)
  • Digoxin (Digitek, Lanoxin)
  • Ethacrynic acid (Edecrin)
  • Laxatives
  • Licorice
  • Lithium (Eskalith, Lithobid)
  • Methotrexate (Rheumatrex, Trexall)
  • NSAIDs
  • Nonsteroidal anti-inflammatory drugs (NSAIDs):
    • Celecoxib (Celebrex)
    • Diclofenac (Cataflam, Voltaren)
    • Etodolac (Lodine)
    • Ibuprofen (Motrin, Advil)
    • Indomethacin (Indocin, Indocin SR)
    • Ketoprofen
    • Ketorolac (Toradol)
    • Meloxicam (Mobic)
    • Naproxen (Naprosyn) or naproxen sodium (Anaprox, Aleve, Naprelan)
    • Nabumetone (Relafen)
    • Oxaprozin (Daypro)
  • Phenytoin (Dilantin, Phenytek)
  • Salicylates:
    • Aspirin (Ecotrin, Bayer, Anacin)
    • Choline magnesium trisalicylate (Trilisate)
    • Diflunisal (Dolobid)
    • Salsalate (Salflex, Disalcid, Amigesic)
  • Sucralfate (Carafate)

Aminoglycoside antibiotics
It is very dangerous to combine aminoglycoside antibiotics with Lasix unless you have an urgent necessity. You could loose your hearing when using these two medications.

Chloral hydrate
There were cases when a person who takes chloral hydrate had taken Lasix during that day, he has had restlessness, high blood pressure, reddening of skin, accelerated rate of heart, sickness or attacks of sweat. Usually, the doctors do not recommend taking these two medications together.

There were cases, when a person had decreased levels of potassium or hypokalemia when he was taking corticosteroids with this medication. So, when you are having a treatment your doctor should check the levels of potassium in your blood and make some measures for its correction if it is needed.

You have more possibility to get gout when you take cyclosporine with Lasix, because such interaction can increase the amount of uric acid.

Digoxin or Lanoxin and Digitek
Patients that use digoxin have to be more careful when they take Lasix. The levels of potassium can be decreased and it is harmful for patients that are on digoxin.

Edecrin or Ethacrynic acid
You can become occasionally deaf if you take ethacrynic acid with Lasix.

Those who are using Lasix should be careful taking laxatives for a long time, since it can cause the low level of potassium in their blood.

A patient can obtain hypokalemia or low levels of potassium on blood if he takes licorice with Lasix for quite a long time. Sometimes it happens when medicine of "licorice" doesn't include real licorice at all. For example some black licorice medications include a flavor of anise instead of real licorice and there is no licorice in red licorice products.

Lithium like Lithobid or Eskalith
The amount of lithium could be increased a lot if you take lithium products with this medication, which later will lead to dangerous side effects. They usually forbid taking diuretics like Lasix with lithium products. Ask your healthcare provider to control the amount of lithium in your blood or maintain the dose of medicine if you are prescribed to use these two medicine together.

When a patient takes this medicine with methotrexane, both drugs will increase their toxicity and Lasix looses its effectiveness. You need to ask your doctor if you may combine these two drugs.

NSAIDs or nonsteroidal anti-inflammatory drugs
The medication looses its effectiveness when you use it wth nonsteroidal anti-inflammatory drugs. This interaction will also make your side effects more dangerous. If this combination makes you suffer a lot, you should ask your doctor to propose another type of medicine that has the same effects as NSAIDs or increase the dose of Lasix.

Other drugs for blood pressure
A patient can get huge blood pressure decrease, when he takes the medicine with other drugs for blood pressure. It can also bring problems to your kidney, if you use the medicine with other specific blood pressure drugs. This can be avoided if you ask your doctor to monitor your treatment more carefully or ask him to adjust the dosing of both drugs.

The action of furosemide will be decreased with phenytoin. The doctor could tell you if you can combine these two medicines at one time.

The amount of salicylate will be increased if you take this medication with salicylate, increasing the danger of side effects. Ask your doctor if you can combine these two medicines.

Sucralfate or Carafate
The effectiveness of Lasix will be decreased when taking it with sucralfate. If you feel that this interaction brings you problems, ask your doctor to advise you another type of medicine that has similar effects or he could increase the dose of the medication.


May be in this article we didn't discuss all the possible interactions with this medicine. You still need to talk to your doctor about your personal interactions with other drugs.
Madnix . Wildsultan

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User discussion about Lasix

12 November 2012
I was looking for the best medicine and now I have it. There are so many tablets, that I was taking, which were other fluid pills that are sold by prescription and some OTC fluid pills, but they didn’t give such effect like this medicine.
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30 January 2013
Does Lasix cause weight gain or bloating of any kind?
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01 March 2013
what should a patient on IV lasix do now that it is on natl backorder???????
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21 March 2013
ellenLooking for this everywhere My Mom needs this 40mg I.V. push, this backorder has been going on for some time. Is there a replacement drug that does the same? Thank You
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11 January 2017
Thank you very helpful info.
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