From the Guidelines
Furosemide (Lasix) is used to treat hyperkalemia by increasing urinary excretion of potassium, and its use is recommended in patients who do not respond to anti-mineralocorticoids or develop hyperkalemia, starting at a dose of 40 mg/day with stepwise increases up to 160 mg/day 1.
Key Points
- Furosemide works by blocking sodium reabsorption in the loop of Henle, creating a more negative electrical potential in the tubular lumen, which promotes potassium secretion.
- The doses of furosemide can be increased simultaneously with anti-mineralocorticoids every 3 to 5 days if weight loss and natriuresis are inadequate, maintaining a ratio of 100 mg:40 mg of anti-mineralocorticoid to furosemide 1.
- Furosemide should be used cautiously in patients with renal impairment, as its effectiveness decreases with declining kidney function, and it works best for hyperkalemia when the patient is adequately hydrated 1.
- Monitoring of electrolytes, particularly potassium, sodium, and magnesium, is essential during furosemide therapy as it can cause electrolyte imbalances.
Clinical Considerations
- In patients with hyperkalemia, furosemide can be used to rapidly lower potassium levels, but its effectiveness may be limited in patients with severe renal impairment 1.
- The use of furosemide in combination with anti-mineralocorticoids may help to maintain normokalemia and achieve rapid natriuresis in patients with ascites due to cirrhosis 1.
- Furosemide should be stopped if severe hypokalemia occurs, and anti-mineralocorticoids should be stopped if severe hyperkalemia occurs 1.
From the Research
Relationship between Hyperkalemia and Furosemide (Lasix)
- Furosemide is a diuretic that can be used to remove potassium from the body in patients with hyperkalemia 2, 3, 4, 5.
- In patients with hyperkalemia, furosemide can be used in combination with other treatments such as insulin and glucose, beta(2)-agonists, and sodium polystyrene to lower serum potassium levels 2, 3, 5.
- Furosemide can be effective in treating hyperkalemia in patients with intact renal function, and hemodialysis may not be necessary in these cases 5.
- However, furosemide can also contribute to the development of hyperkalemia in certain patients, particularly when used in combination with other medications such as captopril and potassium supplements 6.
- It is essential to closely monitor renal function and plasma potassium levels in patients receiving furosemide, especially when used in combination with other medications that can affect potassium homeostasis 6.