Lasix is a diuretic. It blocks the reabsorption of sodium and chlorine ions in the ascending limb of Henle’s loop. It also increases the excretion of potassium, calcium, magnesium from the body.
When administered orally, bioavailability is equal to 64%. Cmax increases with increasing dose. The time to reach the maximum is not dose-dependent and varies widely depending on the patient’s condition. T1/2 is about 2 hours. In plasma, 91–99% binds to a protein, 2.4–4.1% remains in a free state. It is biotransformed mainly in glucuronide. It is excreted in the urine.
The beginning of the diuretic effect when taken orally is already observed within 1 hour, the maximum action is 1–2 hours, the duration is 6–8 hours. With the venous introduction, the beginning of the action is 5 minutes, the maximum effect onset is 30 minutes, the duration is about 2 hours. With intravenous administration, it causes expansion of the veins, quickly reduces preload, reduces pressure in the left ventricle and the pulmonary artery system, reduces systemic pressure.
- Edema syndrome of various origins (cardiac, hepatic, renal after the second month of pregnancy, intoxication);
- Pulmonary and brain edema;
- Arterial hypertension;
- Forced diuresis;
- Renal failure.
- Hypersensitivity (including to other sulfone and sulfonamides);
- Acute glomerulonephritis;
- Renal failure with anuria;
- Hepatic coma;
- Violation of the water-salt balance and hypokalemia/hyponatremia.
Dosage and administration
Lasix is taken orally. It is usually prescribed on an empty stomach.
- With mild edematous syndrome, the initial dose for adults is 20-80 mg;
- In case of persistent edema – the same dosage or increased by 20-40 mg can be prescribed again no earlier than within 6-8 hours until a diuretic effect is obtained;
- Such an individually selected dosage can be applied 1 or 2 times a day.
- The maximum effect is achieved when taking Lasix 2-4 days a week.
Pregnancy and lactation
Lasix during pregnancy should be used according to strict indications and only for a short period of time. During treatment, breastfeeding should be discontinued.
- Dry mouth;
- Metabolic alkalosis;
- Hearing impairment;
- Vision impairment;
- Mild weakness;
- Prostate adenoma;
- Decreased glucose tolerance;
- Acute pancreatitis;
- Allergic reactions (rash, fever, vasculitis, interstitial nephritis);
- In premature infants – nephrocalcinosis.
Lasix increases the risk of intoxication with cardiac glycosides (on the background of glucocorticoids, the likelihood of hypokalemia), nephrotoxic and ototoxic effects of aminoglycosides, cephalosporins, cisplatin. It enhances the effect of curariform agents and increases the reabsorption of lithium in the renal tubules. NSAIDs reduce the diuretic effect.
Before treatment, electrolyte disturbances should be compensated. During treatment with furosemide, it is necessary to control blood pressure, serum electrolytes, and glucose, liver, and kidney function. It is recommended to combine furosemide with potassium-sparing diuretics to prevent hypokalemia. With the simultaneous use of furosemide and hypoglycemic drugs, dose adjustment of the latter may be required. It is not recommended to mix a solution of furosemide in one syringe with any other drugs.