lasix oral 40 mg Uses, Dosage, Side Effects, Precautions &Warnings

lasix 40 mg Uses, Dosage, Side Effects, Precautions &Warnings

lasix 40 mg Generic drug of the therapeutic class: Urologynephrology
active ingredients: Furosemide

What is lasix?

This medicine is indicated in the treatment:

  • oedemas of cardiac or renal origin,
  • oedemas of hepatic origin, most often in combination with a potassium-sparing diuretic,
  • of high blood pressure.

What is Lasix 40 mg used for and indication?

40 mg and 20 mg tablets, 10 mg / ml oral solution and 60 mg LP capsule:
  • Edema of cardiac or renal origin.
  • Edema of hepatic origin, most often in combination with a potassium-sparing diuretic.
40mg and 20mg tablets:
  • Hypertension in patients with chronic renal failure, in case of contraindication to thiazide diuretics (especially when the creatinine clearance is less than 30 ml / min).
10 mg / ml oral solution and 60 mg LP capsule:
  • Hypertension.

lasix dosage

Oral way.

  • Use only the dosing pipette attached to the bottle of lasix oral solution. It can take up to a maximum of 2 ml of oral solution (20 mg furosemide).
  • The dose to be administered is adaptable to the nearest 0,1 ml (that is to the nearest 1 mg) thanks to graduations that go from 0,1 ml in 0,1 ml.
  • lasix oral solution can be diluted in half a glass of water, or in a small amount of milk from the bottle.
  • The dosage is adapted according to the indication and the severity of the affection.


Hypertension :

The recommended starting dose is 20 mg furosemide daily (in the morning).

In case of insufficient efficiency, one can:

  • · Increase doses to 40 mg,
  • · Combine another antihypertensive drug.
  • The dosage of furosemide may be increased beyond 40 mg in case of impaired renal function.

Edema of cardiac, renal or hepatic origin :

The usual dosage is 20 mg (2 ml) to 80 mg (8 ml) daily, divided into 2 doses.

Child and infant

The daily dosage is 1 to 2 mg / kg of body weight, ie 0.5 ml to 1 ml of solution for 5 kg, divided into 1 to 2 doses.

How it works lasix


Salidiuretic action

  • At the usual therapeutic doses, furosemide acts mainly in the ascending limb of Henle’s loop where it inhibits the reabsorption of chlorine and, consequently, sodium. It has an accessory action at the level of the proximal tube and the dilution segment.
  • It increases the renal blood flow in favor of the cortical area. This property is of particular interest in case of association with betablockers which may have the opposite effect.
  • It does not alter glomerular filtration (an increase in glomerular filtration has been demonstrated under certain circumstances). The salidiuretic action increases in proportion to the doses administered and persists in case of renal insufficiency.

Antihypertensive action and other actions

  • It has a haemodynamic action characterized by the decrease of the pulmonary capillary pressure even before the appearance of any diuresis, and by the increase of the capacity of storage of the vascular vascular bed demonstrated by plethysmography (these properties were more particularly studied by IV).
  • Furosemide treats all forms of water-soluble retention with a dose proportional response. Furosemide has an antihypertensive action that results from both sodium depletion and hemodynamic action.

lasix Side Effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Occurrence frequencies may sometimes be determined for adverse effects and are defined as indicated below. An adverse effect is said:

  • · Very common when it occurs in more than 1 in 10 patients
  • · Common when it occurs in less than 1 in 10 patients
  • · Uncommon when it occurs in less than one in 100 patients
  • · Rare when it appears at least dun in 1000
  • · Very rare when it occurs in less than one in 10,000 patients

The following side effects may occur:

  • · Formation of blood clots in a blood vessel especially in the elderly.
  • · In an indeterminate number of patients, retention of urine in the bladder in case of blockage of urine flow (urinary tract obstruction).
  • · In case of severe liver disease (liver failure), possibility of frequent occurrence of brain disorders (hepatic encephalopathy).
  • · Uncommon cases of allergic or non allergic skin reactions, itching associated or not with the appearance of raised spots on the skin, such as stinging of nettles (urticaria), bullous reactions, bullous pemphigoid (Skin condition characterized by the presence of bubbles), Uncommonly exaggerated reaction of the skin after exposure to the sun and UV (photosensitization), redness on the skin and mucous membranes (erythema multiforme), and in an indeterminate number of patients bubble eruption with detachment of the skin that can rapidly spread throughout the body and endanger the patient (Stevens-Johnson syndrome, Lyell syndrome), acute generalized exanthematous pustulosis (PEAG ) (acute febrile rash due to the drug) and a drug hypersensitivity reaction manifested by a generalized rash, high fever, disorders of the blood elements (increased number of certain white blood cells) and possibly liver, kidney, lung and heart disease (syndrome). of DRESS).
  • · Other signs of allergic reactions: rarely, fever, increase of certain white blood cells (hypereosinophilia), potentially serious allergic reactions, especially sudden malaise with significant drop in blood pressure, rapid heart rate and difficulty breathing (anaphylactic and / or anaphylactoid reactions) ).
  • · Uncommonly, small red-purple spots on the skin (purpura), rarely inflammation and alteration of the blood vessels (vasculitis).
  • · Rarely, tingling (paresthesia).
  • · Digestive disorders such as, infrequently, nausea, and rarely, vomiting and diarrhea.
  • · Very rarely, liver or pancreas damage.
  • · Rarely, kidney damage (interstitial nephropathy).
  • · Uncommonly, impaired hearing especially in people who have kidney disease (kidney failure or nephrotic syndrome), or who also use some antibiotic drugs including aminoglycoside family. Infrequently, cases of deafness (which may be irreversible) have been reported.

· Visible changes during a blood test may appear:

  • Frequent decrease in the amount of potassium in the blood (hypokalemia).
  • Frequent decrease in the amount of sodium in the blood (hyponatremia).
  • A very frequent decrease in the total volume of blood in the body (hypovolemia) with a significant drop in blood pressure during the transition from sitting to standing, which may be accompanied by vertigo and / or malaise (orthostatic hypotension).
  •  A decrease in the number of white blood cells (neutropenia in rare cases, agranulocytosis in very rare cases), a decrease in the number of white blood cells, red blood cells and platelets (bone marrow failure in very rare cases), in some cases uncommon decreased platelets in the blood (thrombocytopenia).
  • A frequent discreet increase in the level of uric acid in the blood (uricemia) that can cause a gout attack.
  • Increased blood urea in an indeterminate number of patients.
  • A very frequent increase in creatinine in the blood.
  • A very frequent increase in fats (triglycerides) and frequent cholesterol in the blood.
  • An increase in the blood sugar level.
  • Very frequent changes in the amount of minerals and water in your body that can lead to dehydration.
  • A decrease in blood potassium associated with a decrease in blood chloride and acid-base disorder as well as an increase in aldosterone secretion (pseudo-Bartter syndrome) in an indeterminate number of patients,

· In an undetermined number of very premature infants, cases of calcium salt deposits in the kidneys (renal calcifications) have been observed during treatment with high doses of injectable furosemide.

· Not known: acceleration or intensification of an inflammatory disease including skin (systemic lupus erythematosus), dizziness, fainting and unconsciousness headache, severe dizziness of the muscles (often in a context of significant reduction of potassium in the blood)

lasix Interactions

Hypokalaemic drugs

  • Hypokalemia is a factor favoring the development of cardiac arrhythmias (torsades de pointes, in particular) and increasing the toxicity of certain drugs, for example digoxin. As a result, medications that can lead to hypokalemia are involved in a large number of interactions.
  • These are hypokalaemic diuretics, alone or in combination, stimulant laxatives, glucocorticoids, tetracosactide and amphotericin B (route IV).

Hyponatraemic drugs

  • Some drugs are more frequently involved in the occurrence of hyponatremia. These are diuretics, desmopressin, antidepressants inhibiting reuptake of serotonin, carbamazepine and oxcarbazepine. The combination of these drugs increases the risk of hyponatremia.

Ototoxic drugs

  • Joint use of drugs with ototoxicity increases the risk of cochleobuccal involvement. If such an association is needed, the monitoring of the auditory function should be strengthened.
  • The drugs involved include glycopeptides such as vancomycin and teicoplanin, aminoglycosides, organoplatin and loop diuretics.

Associations advised against


  • Increased lithemia with signs of overdose, such as during a deodorized diet (decreased urinary excretion of lithium). If the combination can not be avoided, strict monitoring of lithemia and adaptation of the lithium dosage.

Associations subject to precautions for use

  Acetylsalicylic acid for anti-inflammatory doses of acetylsalicylic acid (≥ 1 g per dose and / or ≥ 3 g per day) or for analgesic or antipyretic doses (≥ 500 mg per dose and / or <3 g per day)

  • Acute renal failure in the dehydrated patient by reduction of glomerular filtration secondary to a decrease in renal prostaglandin synthesis. Moreover, reduction of the antihypertensive effect.
  • To moisturize the patient; Look at the kidney function at the start of the treatment.

Nonsteroidal anti-inflammatory drugs

  • Acute renal failure in the patient at risk (elderly and / or dehydrated) by reduction of glomerular filtration (inhibition of vasodilator prostaglandins due to nonsteroidal anti-inflammatory drugs). Moreover, reduction of the antihypertensive effect.
  • Hydrate the patient and monitor kidney function at the beginning of treatment.

 Other hypokalaemic agents

Increased risk of hypokalemia. Monitoring of the serum potassium with correction if necessary.


Hypokalemia favoring the toxic effects of digitalis. Correct any hypokalemia beforehand and perform clinical, electrolytic and electrocardiographic monitoring.

 Potassium sparing diuretics, alone or in combination (amiloride, potassium canrenoate, eplerenone, spironolactone, triamterene)

The rational combination, useful for some patients, does not exclude the occurrence of hypokalemia or, especially in the renal failure and the diabetic, hyperkalemia. Monitor serum potassium, possibly ECG, and if appropriate, reconsider treatment.


  • Increased nephrotoxic and ototoxic risks of aminoglycosides (functional renal failure related to dehydration caused by diuretics).
  • Possible association under monitoring of the state of hydration and renal and cochleo-vestibular functions and possibly plasma concentrations of aminoglycoside.

Phenytoin (and, by extrapolation, fosphenytoin)

Decreased diuretic effect up to 50%. May use higher doses of furosemide.


Risk of symptomatic hyponatremia. Clinical and biological surveillance. If possible, use another class of diuretics.

 ACE inhibitors, angiotensin II receptor antagonists

Risk of sudden hypotension and / or acute renal failure when initiating or increasing the dose of an ACE inhibitor or angiotensin II antagonist in pre-existing water-soluble depletion.

In arterial hypertension , when previous diuretic therapy may have resulted in sodium depletion, the following should be done:

  •  Stop the diuretic for 3 days before starting treatment with ACE inhibitor or angiotensin II antagonist and reintroduce a hypokalaemic diuretic if necessary later
  •  Give reduced initial doses of ACE inhibitors or the angiotensin II antagonist and gradually increase the dosage.

In congestive heart failure treated with diuretics , start with a very low dose of ACE, possibly after a dose reduction of the associated hypokalaemic diuretic.

In all cases , monitor renal function (serum creatinine) in the first few weeks of treatment with ACE inhibitors or angiotensin II antagonists.

+        Drugs that may give torsades de pointes: class Ia antiarrhythmics (quinidine, hydroquinidine, disopyramide) and class III (amiodarone, sotalol, ibutilide, dofetilide), certain phenothiazine neuroleptics (chlorpromazine, cyamemazine, fluphenazine, levomepromazine, pipotiazine), benzamides (amisulpride, sulpiride, sultopride, tiapride), butyrophenones (droperidol, haloperidol, pipamrenone), other neuroleptics (pimozide, sertindole, flupentixol, zuclopenthixole), others: bepridil, cisapride, diphemanil, dolasetron IV, dronedarone, spiramycin IV, erythromycin IV , mizolastine, levofloxacin, halofantrine, lumefantrine, pentamidine, vincamine IV, moxifloxacin, mequitazine, methadone, pracalopride, toremifene, arsenious, citalopram, escitalopram, …

Higher risk of ventricular arrhythmias, especially torsades de pointes. Correct all hypokalemia before administering the product and perform clinical, electrolytic and electrocardiographic monitoring.


Lactic acidosis due to metformin, triggered by a possible functional renal failure related to diuretics and more particularly to diuretics of the loop. Do not use metformin when serum creatinine exceeds 15 mg / l (135 μmol / l) in men and 12 mg / l (110 μmol / l) in women.

 Iodinated contrast media

In case of dehydration caused by diuretics, increased risk of acute functional renal failure, especially when using large doses of iodinated contrast media. Rehydration before administration of the iodized product.


Increased risk of hypotension, especially orthostatic. Blood pressure monitoring and dosage adjustment of the antihypertensive if necessary.

Associations to consider


  • Risk of increased serum creatinine without change in ciclosporin blood concentrations, even in the absence of water-soluble depletion. Also, risk of hyperuricemia and complications like gout.


  • Increased risk of hypotension, especially orthostatic.

 Imipraminic antidepressants

  • Increased risk of hypotension, especially orthostatic.


  • Increased risk of hypotension, especially orthostatic.

 Urologic blockers: alfuzosin, doxazosin, prazosin, terazosin, tamsulosin

  • Increase of the hypotensive effect. Risk of increased orthostatic hypotension.

 Alpha Blocker Antihypertensives

  • Increase of the hypotensive effect. Increased risk of orthostatic hypotension.


  • Risk of addition of ototoxic and / or nephrotoxic effects.

Nitrate and related derivatives

  • Increased risk of hypotension, especially orthostatic.

lasix Warnings and Precautions

Special warnings

With lithium, the combination is not recommended .

By accidental intake of furosemide, hypovolemia with dehydration may occur .

  • In patients with hepatocellular insufficiency, treatment should be carried out with caution under strict hydroelectrolytic monitoring, given the risk of hepatic encephalopathy (see Precautions for use). The interruption of the treatment must then be immediate.
  • Taking furosemide in case of partial obstruction of the urinary tract may expose patients to urinary retention. Close monitoring of diuresis should therefore be initiated, particularly at the beginning of treatment with furosemide.
  • Furosemide is a sulfonamide. The possibility of cross-sensitization with other sulfonamides, especially antibacterials, remains theoretical and not validated clinically.
  • Cases of photosensitivity reactions have been reported with furosemide .
  • If photosensitivity reactions occur during treatment, it is recommended to stop the treatment. If re-administration of the treatment is essential, it is recommended to protect areas exposed to the sun or artificial UVA.
  • This drug contains sorbitol. Its use is not recommended in patients with fructose intolerance (rare hereditary disease).
  • This medicine contains “parahydroxybenzoate” and may cause allergic reactions (possibly delayed).
  • This medicine contains an azo coloring agent (E110: orange-yellow S) and may cause allergic reactions.

Precautions for use

Furosemide treatment requires special monitoring and dose adjustment for patients with:

  • · Hypotension, especially in patients at risk of cerebral dischemia, coronary artery disease or other circulatory insufficiency,
  • · Hepatorenal syndrome (renal failure associated with severe hepatic impairment),
  • · Hypoproteinemia, especially in case of nephrotic syndrome: possible reduction of the effects of furosemide and potentiation of adverse effects, in particular of lototoxicity.

Symptomatic hypotension causing dizziness, fainting, or loss of consciousness may occur in some patients treated with furosemide, particularly in elderly patients, patients taking other treatments that may cause hypotension, and in patients with other medical conditions that may cause hypotension.

Hydroelectrolytic balance:

· Natremia:

  • It must be checked before treatment is started, and then regularly thereafter. Any diuretic treatment can indeed cause hyponatremia, with sometimes serious consequences.
  • Since the decline in serum sodium may initially be asymptomatic, regular monitoring is therefore essential and should be even more frequent in the at-risk populations represented by the elderly, a fortiori undernourished, and cirrhotic.

· Kaliemia:

Potassium depletion with hypokalemia is the major risk of loop diuretics. The risk of hypokalemia (<3.5 mmol / l) must be prevented in certain at-risk populations represented by elderly and / or malnourished and / or polymedicated patients, cirrhotic patients with edema and ascites, coronary insufficient heart. Hypokalemia increases the cardiac toxicity of digitalis and the risk of rhythm disorders. In patients with a long QT gap at the ECG of congenital or drug origin, hypokalemia promotes the occurrence of severe rhythm disorders, particularly torsades de pointes, which are potentially fatal, especially in the presence of bradycardia. In all cases, more frequent controls of serum potassium are needed.

· Blood glucose:

  • The hyperglycemic effect is modest. Blood glucose control will be strengthened in diabetics and pre-diabetics.

· Uricemia:

  • Furosemide-induced hydrosoduced depletion reduces the urinary excretion of uric acid. In hyperuricemic patients, the tendency to gout can be increased. It should be careful in the gouty.

· Creatininemia:

  • Regular control of serum creatinine is generally recommended during treatment with furosemide.
  • Close monitoring of patients at risk of significant hydroelectrolytic disorders (vomiting, diarrhea, hypersudation,). Dehydration, hypovolemia or acid-base imbalance requires corrective treatment and may result in temporary discontinuation of therapy.

Concomitant use with risperidone:

  • In placebo-controlled trials with risperidone in demented elderly patients, a higher incidence of mortality was observed in patients treated with furosemide plus risperidone (7.3%, mean age 89 years, range 75-97 years). compared to patients treated with risperidone alone (3.1%, mean age 84 years, range 70-96 years) or furosemide alone (4.1%, mean age 80 years, range 67-90 years).
  • The concomitant use of risperidone with other diuretics (mainly low-dose thiazide diuretics) has not been associated with similar findings.
  • No pathophysiological mechanism was identified to explain this effect, and no consistent pattern of death was observed.
  • However, caution is necessary and the benefit / risk ratio of this combination or concomitant treatment with other potent diuretics should be considered prior to any use decision.
  • No increase in mortality has been observed in patients taking other diuretics as concomitant treatment with risperidone. Regardless of the treatment, dehydration is a risk factor for mortality and should be carefully avoided in elderly patients with dementia .
  • Lexacerbation or activation of systemic lupus erythematosus is possible.

Sportsmen :

  • The attention of athletes will be drawn to the fact that this specialty contains an active ingredient that can induce a positive reaction of the tests performed during doping controls.

Newborns and premature babies :

  • In neonates and premature infants, prolonged use of high-dose furosemide with a risk of nephrocalcinosis and / or intra-renal lithiasis, it is advisable to carry out renal ultrasound surveillance.
  • This medicine contains 12.3% vol ethanol (alcohol), ie 99 mg per ml, equivalent to 2.4 ml of beer, 1 ml of wine. The use of this drug is dangerous in alcoholic subjects and should be taken into account in pregnant or breastfeeding women, children and high-risk groups such as hepatic insufficiency or epileptics.
  • This medicine contains sodium. The sodium level is less than 1 mmol per dose, ie “sodium-free”.



  • Studies in animals have shown a teratogenic effect.
  • In clinical studies, there are currently no data of sufficient relevance to evaluate a possible malformative effect of furosemide when administered during pregnancy.
  • In general, furosemide administration should be avoided in pregnant women and should never be prescribed during physiological edema (and therefore not requiring treatment) of pregnancy. Diuretics can, in fact, lead to fœtoplacental ischemia, with a risk of fetal hypotrophy. Fetal growth should be closely monitored. Diuretics (in oral form) nevertheless remain an essential part of the treatment of edema of cardiac, hepatic and renal origin occurring in pregnant women.


  • Furosemide is excreted in breast milk. The risk of adverse effects on the newborn can not be excluded. On the other hand, loop diuretics reduce milk secretion and lactation is inhibited from a single 40 mg dose.
  • Therefore, it is best not to breastfeed if you are taking furosemide.

What is  Forms and Composition ?


lasix: Breakable
40 mg tablet:  Box of 30.

Hospital model: Box of 100.
Oral solution at 10 mg / ml:   60 ml bottle, with dosing pipette. lasix Low: 20 mg tablet:   Box of 30.Hospital model: Box of 100. lasix Delay: 60 mg prolonged-release capsule:  Box of 30.Hospital model: Box of 100.



Compressed : p cp
furosemide 40 mg
  • Excipients: maize starch, pregelatinized maize starch, talc, anhydrous colloidal silica, magnesium stearate, lactose monohydrate.
  • Excipient with known effect: lactose.
Drinkable solution : p ml
furosemide 10 mg
  • Excipients: sorbitol, glycerol, methyl parahydroxybenzoate, propyl parahydroxybenzoate, orange flavor (alpha-pinene, beta-pinene, myrcene, limonene, octanal, decanal, linalool, ethanol), orange-yellow S (E110), ethanol 96% , sodium hydroxide, purified water.
  • Excipients with known effect: yellow orange S (E110), ethanol, parahydroxybenzoate, sorbitol.

Alcohol content: 11.7% v / v.

1 scale of the dosing pipette corresponds to 0.1 ml of solution, ie 1 mg of furosemide.

Low lasix:

Compressed : p cp
furosemide 20 mg
  • Excipients: maize starch, pregelatinized maize starch, lactose monohydrate, talc, colloidal anhydrous silica, magnesium stearate.
  • Excipient with known effect: lactose.

lasix Delay:

LP capsule: p capsule
furosemide 60 mg
  • Excipients: sucrose, corn starch, povidone, talc, shellac, stearic acid, aluminum hydroxide. Capsule
  • shell: gelatin, titanium dioxide, yellow iron oxide, indigotine.
  • Excipient with known effect: sucrose.


Edrug-online contains comprehensive and detailed information about drugs available in the medical field, and is divided into four sections:

general information:

Includes a general description of the drug, its use, brand names, FAQs, and relevant news and articles

Additional information:

General explanation about dealing with the medicine: how to take the medicine, the doses and times of it, the start and duration of its effectiveness, the recommended diet during the period of taking the medicine, the method of storage and storage, recommendations in cases for forgetting the dose and instructions to stop taking the drug and take additional doses.

Special warnings:

For pregnant and breastfeeding women, the elderly, boys and drivers, and use before surgery.

Side effects:

It treats possible side effects and drug interactions that require attention and its effect on continuous use.

The information contained in this medicine is based on medical literature, but it is not a substitute for consulting a doctor.

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