Furosemide, also known as Lasix, powerfully inhibits sodium-potassium-chloride co-transport in the thick ascending limb of the loop of Henle. This specific action dramatically reduces sodium, potassium, and chloride reabsorption.
Consequences of Sodium Reabsorption Inhibition
By blocking this crucial reabsorption process, furosemide increases the amount of sodium, chloride, and water excreted in the urine. This leads to a significant increase in urine output (diuresis) and a reduction in blood volume.
Impact on Blood Pressure and Edema
The decreased blood volume directly lowers blood pressure. This diuretic effect makes furosemide a valuable treatment for conditions characterized by fluid retention, such as edema associated with heart failure, liver cirrhosis, and kidney disease.
Additional Effects
Furthermore, furosemide’s action affects calcium and magnesium handling. It slightly increases calcium excretion and can lead to magnesium loss, which is something to consider during long-term treatment. This makes monitoring of serum electrolytes important.
Summary Table: Key Effects of Furosemide
| Renal System | Increased sodium, potassium, chloride, and water excretion | Diuresis, decreased blood volume |
| Cardiovascular System | Decreased blood pressure | Treatment of hypertension and edema |
| Electrolyte Balance | Increased calcium and magnesium excretion | Potential for hypokalemia and hypomagnesemia |
Specific Dosage Considerations
Furosemide dosage depends on individual needs and response. A physician should carefully monitor patients receiving furosemide, regularly assessing blood pressure, electrolyte levels, and kidney function.
