From the Guidelines
The combination of Furosemide (Lasix) and Hydrochlorothiazide (HCTZ) is effective in treating edema by providing a synergistic diuretic effect, with Furosemide acting as a loop diuretic and HCTZ as a thiazide diuretic, allowing for increased urine output and reduction of fluid retention 1.
Mechanism of Action
- Furosemide works by inhibiting the sodium-potassium-chloride cotransporter in the ascending limb of the loop of Henle, leading to increased excretion of sodium, chloride, and water 1.
- Hydrochlorothiazide acts by inhibiting the sodium-chloride cotransporter in the distal convoluted tubule, resulting in increased excretion of sodium and water 1.
Clinical Use
- The combination of Furosemide and HCTZ is commonly used in patients with heart failure who have resistant edema, as it allows for a more potent diuretic effect than either medication alone 1.
- The dose of Furosemide and HCTZ should be tailored to the individual patient's needs, with careful monitoring of potassium, sodium, and creatinine levels to avoid dehydration, hypovolemia, hyponatremia, or hypokalemia 1.
Important Considerations
- Patients with mild heart failure may respond favorably to low doses of Furosemide, while those with moderate or severe heart failure may require higher doses or combination therapy with HCTZ 1.
- Dietary sodium restriction is also recommended to enhance the effectiveness of diuretic therapy and prevent diuretic resistance 1.
From the Research
Effect of Furosemide and Hydrochlorothiazide on Edema
The combination of Furosemide and Hydrochlorothiazide has been studied in various clinical trials to assess its effect on edema. The results are as follows:
- In a study published in 1996 2, the addition of Hydrochlorothiazide to high-dose Furosemide resulted in a significant reduction in body weight, with a mean reduction of 6.7 kg per patient.
- A study published in 2017 3 found that the combination of Furosemide and Hydrochlorothiazide did not increase the diuretic effect of Furosemide in patients with end-stage renal disease.
- In a randomized trial published in 2005 4, Hydrochlorothiazide was found to increase the fractional excretion of sodium and chloride more than Furosemide in hypertensive patients with severe renal failure.
- A prospective randomized trial published in 2023 5 found that a combination of oral Furosemide, Hydrochlorothiazide, and Amiloride was non-inferior to intravenous Furosemide in treating resistant nephrotic syndrome, with a significant difference in weight change from baseline between the two groups.
- A pilot study published in 2012 6 found that the association of Furosemide and Hydrochlorothiazide increased the fractional excretions of sodium and chloride, and was more efficient on blood pressure control, compared to either diuretic alone.
Key Findings
- The combination of Furosemide and Hydrochlorothiazide can be an effective treatment for edema, particularly in patients with severe renal failure or resistant nephrotic syndrome 2, 5.
- The addition of Hydrochlorothiazide to Furosemide can increase the diuretic effect, but this may not always be the case, particularly in patients with end-stage renal disease 3.
- Hydrochlorothiazide may be more effective than Furosemide in increasing the fractional excretion of sodium and chloride in certain patient populations 4, 6.
- The combination of Furosemide and Hydrochlorothiazide may have a more pronounced effect on blood pressure control compared to either diuretic alone 6.