Class: Cardiovascular System
Dosage Form: Ampoules
Description: Loop diuretic
Manufacturer: Sanofi Aventis
Each 2 ml ampoule contains:
Lasix injection solution is indicated in conditions where adequate diuresis is not obtained with oral administration or with lower intravenous doses of Lasix.
- Edema due to cardiac and hepatic disease (ascites)
- Edema due to renal disease (in the nephrotic syndrome, therapy of the underlying diseases has precedence)
- Acute cardiac insufficiency, especially in pulmonary edema (administration in conjunction with other therapeutic measures)
- Supportive measures in brain edema
- Edema due to burns
- Hypertensive crisis (in addition to other antihypertensive measures)
- To support forced diuresis in poisoning
Lasix is contraindicated in:
- Hepatic coma
- Severe hypokalaemia
- Hyponatraemia and/or hypovolaemia with or without hypotension
- Hypersensitivity to sulfonamides
The following interactions are noted:
- When a cardiac glycoside is administered concurrently it should be remembered that potassium deficiency increases the sensitivity of the myocardium to digitalis. When a glucocorticoid is administered during diuretic treatment the potassium.lowering effect of the steroid should be borne in mind
- Furosemide may aggravate the nephrotoxic effects of certain antibiotics (e.g. aminoglycosides). In patients with antibiotic-induced renal impairment, furosemide should be used with caution
- It should be borne in mind that the ototoxicity of aminoglycoside antibiotics (e.g. kanamycin, gentamicin, tobramycin) may be potentiated when furosemide is used concurrently. The hearing defects that result may be irreversible. Therefore, this drug combination should be restricted to vital indications.
- As the concomitant administration of cisplatin and furosemide carries the risk of inducing hearing defects, the two drugs should not be used simultaneously
- Furosemide sometimes diminishes the potency of other drugs (e.g. the effect of antidiabetics and pressor amines) or potentiates their effect (e.g. in the case of salicylates, lithium and curaremimetic muscle relaxants)
- The action of other hypotensive drugs may be potentiated by furosemide, Certain non-steroid anti-inflammatory agents (e.g, indomethacin) may antagonise the action of furosemide
As with other diuretics, electrolyte and water balance may be disturbed as a result of diuresis after prolonged therapy. Mainly at the start of treatment, excessively rapid mobilisation of edema, particularly in elderly patients, may give rise to circulatory disturbances, such as a feeling of pressure in the head, vertigo or visual impairment; in extreme cases, dehydration, hypovolaemia, circulatory collapse and blood coagualtion disorders may occur. However, with individualized dosage of Lasix, acute haemodynamic reactions are generally not to be expected,although diuresis sets in rapidly. In common with other saluretics, potassium depletion may be brought about, especially in cases of low- potassium diet, vomiting or chronic diarrhoea (abuse of laxatives). In addition, diseases such as cirrhosis of the liver may cause a predisposition to potassium deficiency states. Appropriate surveillance and replacement therapy are necessary in such cases.
If salt intake is restricted too much, sodium deficiency may produce orthostatic hypotension, calf muscle cramps, anorexia, weakness, dizziness, drowsiness, vomiting and confusional states.
The serum calcium level may be reduced under furosemide therapy, in very rare cases tetany has been observed. Calcification of the kidneys may occur in premature babies.
Allergic reactions (e.g. rashes) and blood dyscrasias (leukopenia, agranulocytosis, anaemia, th rombocytopenia) may occasionally be observed. Anaphylactic shock, though rare, is an acute life- threatening reaction (for recommended measures see below).
Symptoms of obstructive uropathies (e.g. in hydronephrosis, prostatic hypertrophy, ureterostenosis) may become manifest or aggravated under the action of diuretics.
In common with other diuretics, the treatment with Lasix may induce a transient rise in serum creatinine and urea.
It should be remembered that an increase in uric acid concentration in the blood may precipitate attacks of gout in predisposed patients.
In rare cases manifest diabetes mellitus may be aggravated by furosemide treatment and latent diabetes may become manifest.
Isolated cases of acute pancreatitis have been reported in which the treatment with saluretics over several weeks was considered a causal factor, including also a few cases following therapy with furosemide. Disorders of hearing after furosemide are rare and in most cases reversible. This possibility should be borne in mind, especially if furosemide is injected too rapidly and in particular in patients with renal insufficiency (See mode and duration of treatment). A pre-existing metabolic alkalosis may be aggravated by furosemide treatment (e.g. in decompensated cirrhosis of the liver).
In individual cases, the ability to cope with road traffic or to operate machinery may be impaired, especially at the commencement of treatment, when changing over from other drugs, or when alcohol is consumed during furosemide therapy.
Dosage and Administration:
Unless otherwise prescribed by the physician, the initial dose for adults and adolescents over 15 years is 20 to 40 mg Lasix (1-2 ampoules) intravenously or intramuscularly.
If after a single dose of 20 to 40 mg Lasix (1-2 ampoules) the diuretic effect is not satisfactory, the dose may be step-wise increased, at two-hourly intervals, by 20 mg (1 ampoule) each time, until satisfactory diuresis is obtained. The individual dose thus established should then be given once or twice daily.
a) Acute pulmonary edema:
- An initial dose of 40 mg Lasix (2 ampoules) is administered intravernously. [f-the patient’s condition requires it, a further dose of 20-40 mg Lasix (1-2 ampoules) is injected after 20 minutes.
b) Forced diuresis:
- 20-40 mg Lasix (1-2 ampoules) is given in addition to infusion of electrolyte solution
- Further treatment depends on the elimination of urine and must include substitution of the fluid and electrolyte losses
- In poisoning with acid or basic substances the elimination rate may be further increased by alkalisation or acidification, respectively, of the urine
c) Infants and children under 15 years:
- Parenteral administration (if necessary, continuous drip infusion) is indicated only in life-threatening conditions
- For intravenous or intramuscular injection the dosage schedule is 1 mg furosemide per kg body weight up to a daily maximum of 20 mg Lasix (1 ampoule). Therapy should be changed to oral administration as soon as possible
2. Mode and Duration of Treatment:
The duration of treatment is at the physician’s discretion.
Intravenous or intramuscular administration of Lasix 20 mg is indicated in all cases where intestinal absorption is impaired or rapid dehydration is necessary.
Intravenously, Lasix 20 mg should be injected slowly. The rate of injection of 4 mg per minute should not be exceeded.
By a diet too low in salt, the glomerular filtration rate may be reduced and the action of saluretics impaired. In these cases the diuretic action of Lasix 20 mg is enhanced by an increase of the sodium chloride intake.
During long-term treatment, serum creatinine and urea and also plasma electrolytes, in particular potassium, calcium, chloride and bicarbonate, should be regularly checked.
Furosemide, being an anthranilic acid derivative, dissolves in alkaline media with salt formation. The solution for parenteral application contains the sodium salt of the carboxylic acid without a solubilizer. The solution has a pH of about 9 but no buffer capacity, which means that the drug may precipitate at pH values below 7. If the ready-to-use solution has a pH ranging from weakly alkaline to neutral, the mixtures may be used for up to 24 hours.
Lasix 20 mg must not be mixed with other drugs in the same injection syringe.
1. Emergency measures to be taken if anaphylactic shock occurs:
The following emergency measures are generally recommended: At the first signs (sweating, nausea, cyanosis) interrupt the injection immediately but leave the venous canula in place or perform various canulation. In addition to the usual emergency measures, ensure that the patient is kept flat with the legs raised and airways patent.
2. Emergency drug therapy:
Immediate epinephrine (adrenaline) iv.: dilute 1 ml of commercially available epinephrine solution 1:1000 to 10 ml. In the first instance slowly inject I ml of this dilution (equivalent to 0.1mg epinephrine) while monitoring pulse and blood pressure (watch for disturbances of cardiac rhythm). The administration of epinephrine may be repeated. Then glucocorticoids IV: e.g. 250 – 1000 mg
methylprednisolone. The glucocorticoid administration may be repeated.
Subsequently volume substitution IV: e.g. plasma expanders, human albumin, balanced electrolyte solution.
Other therapeutic measures: artificial respiration, oxygen inhalation, calcium, antihistaminics.
Although administration of Lasix 20 mg only rarely leads to hypokalaemia, a potassium-rich diet (lean meat, potatoes, bananas, tomatoes, cauliflower, spinach, dried fruit, etc.) is always advisable.
Box of 3 or 5 ampoules of 2 ml each.
Store at room temperature, below 25°C.