What is the relationship between Lasix (Furosemide) and Hyponatremia?

From the Guidelines

Lasix (Furosemide) can cause or exacerbate hyponatremia, particularly in patients with cirrhosis and ascites.

Relationship between Lasix and Hyponatremia

• Furosemide, a loop diuretic, can lead to hypovolaemic hyponatraemia due to its potent diuretic effect, which can result in excessive loss of sodium and water 1.
• The management of hypovolaemic hyponatraemia during diuretic therapy involves discontinuation of diuretics and expansion of plasma volume with normal saline 1.
• Caution should be used when starting treatment with diuretics in patients with hyponatremia, and patients should be submitted to frequent clinical and biochemical monitoring 1.
• Diuretics, including furosemide, should be discontinued if there is severe hyponatremia (serum sodium concentration <120 mmol/L) 1.
• The dose of diuretics, including furosemide, should be reduced and discontinued later, whenever possible, to maintain patients free of ascites with the minimum dose of diuretics 1.

From the FDA Drug Label

As with any effective diuretic, electrolyte depletion may occur during Furosemide tablets therapy, especially in patients receiving higher doses and a restricted salt intake All patients receiving Furosemide tablets therapy should be observed for these signs or symptoms of fluid or electrolyte imbalance (hyponatremia, hypochloremic alkalosis, hypokalemia, hypomagnesemia or hypocalcemia): dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, arrhythmia, or gastrointestinal disturbances such as nausea and vomiting. The relationship between Lasix (Furosemide) and Hyponatremia is that Furosemide can cause electrolyte depletion, including hyponatremia, especially in patients receiving higher doses and a restricted salt intake. Patients receiving Furosemide should be observed for signs or symptoms of fluid or electrolyte imbalance, including hyponatremia 2.

From the Research

Relationship between Lasix (Furosemide) and Hyponatremia

The relationship between Lasix (Furosemide) and hyponatremia is complex and has been studied in various contexts.

• Furosemide can be used to treat hyponatremia in certain conditions, such as severe heart failure 3 and syndrome of inappropriate antidiuresis (SIAD) 4.
• In patients with severe heart failure, furosemide can promote natriuresis and correction of hyponatremia when used in combination with captopril 3.
• However, in patients with SIAD, furosemide with sodium chloride supplement in combination with fluid restriction did not show benefits in correction of hyponatremia compared with treatment with fluid restriction alone 4.
• Furosemide therapy can also decrease the urine to plasma osmolality ratio and increase the fractional sodium reabsorption in diluting segments, but it does not cause hyponatremia in patients with chronic renal failure 5.
• Combination of hypertonic saline and low-dose furosemide can be an effective treatment for refractory congestive heart failure with hyponatremia 6.
• Furosemide appears to be safer than thiazide diuretics in terms of risk of hyponatremia, and can be administered to patients with previous thiazide-induced hyponatremia without risk of recurrent hyponatremia 7.

Key Findings

• Furosemide can be used to treat hyponatremia in certain conditions, but its effectiveness depends on the underlying condition and the presence of other medications.
• Furosemide can promote natriuresis and correction of hyponatremia when used in combination with other medications, such as captopril.
• Furosemide therapy can have various effects on water and electrolyte metabolism, including decreasing the urine to plasma osmolality ratio and increasing the fractional sodium reabsorption in diluting segments.
• Combination of hypertonic saline and low-dose furosemide can be an effective treatment for refractory congestive heart failure with hyponatremia.
• Furosemide appears to be safer than thiazide diuretics in terms of risk of hyponatremia.

Conditions and Medications

• Severe heart failure: furosemide can promote natriuresis and correction of hyponatremia when used in combination with captopril 3.
• Syndrome of inappropriate antidiuresis (SIAD): furosemide with sodium chloride supplement in combination with fluid restriction did not show benefits in correction of hyponatremia compared with treatment with fluid restriction alone 4.
• Chronic renal failure: furosemide therapy can decrease the urine to plasma osmolality ratio and increase the fractional sodium reabsorption in diluting segments, but it does not cause hyponatremia 5.
• Refractory congestive heart failure with hyponatremia: combination of hypertonic saline and low-dose furosemide can be an effective treatment 6.
• Thiazide-induced hyponatremia: furosemide appears to be safer than thiazide diuretics in terms of risk of hyponatremia, and can be administered to patients with previous thiazide-induced hyponatremia without risk of recurrent hyponatremia 7.