What is the use of Metolazone (Zaroxolyn)?

From the Guidelines

Metolazone (Zaroxolyn) is primarily used as a diuretic in the treatment of hypertension and heart failure.

Uses of Metolazone

• It is a thiazide-like diuretic that can be used in patients with mild fluid retention, particularly those with hypertension and heart failure 1.
• In cases of severe chronic heart failure, metolazone can be added to loop diuretics, with frequent monitoring of creatinine and electrolytes 1.
• The usual dose of metolazone is 2.5-5 mg per day, taken once daily 1.

Mechanism of Action

• Metolazone acts by inhibiting the reabsorption of sodium or chloride at specific sites in the renal tubules, increasing urinary sodium excretion and decreasing physical signs of fluid retention 1.
• It is less effective than loop diuretics in patients with severely impaired renal function, but can be used in combination with loop diuretics in these cases 1.

Clinical Considerations

• Metolazone should be used with caution in patients with significant renal impairment, as it can worsen renal function 1.
• Patients taking metolazone should be monitored for signs of hypokalemia, hyponatremia, and hypotension, and for changes in renal function and electrolyte levels 1.

From the FDA Drug Label

Metolazone tablets, USP, are indicated for the treatment of salt and water retention including: edema accompanying congestive heart failure; edema accompanying renal diseases, including the nephrotic syndrome and states of diminished renal function Metolazone tablets, USP, are also indicated for the treatment of hypertension, alone or in combination with other antihypertensive drugs of a different class.

The use of Metolazone (Zaroxolyn) is for the treatment of:

• Edema accompanying congestive heart failure
• Edema accompanying renal diseases, including the nephrotic syndrome and states of diminished renal function
• Hypertension, alone or in combination with other antihypertensive drugs of a different class 2

From the Research

Uses of Metolazone (Zaroxolyn)

• Metolazone is a potent thiazide-like diuretic used in the treatment of various conditions, including:
  • Edema associated with congestive heart failure 3, 4, 5, 6
  • Nephrotic syndrome 3
  • Ascites due to liver disease 7
  • Refractory heart failure 4, 5, 6
• Metolazone is often used in combination with loop diuretics to enhance diuresis in patients with refractory heart failure 4, 5, 6
• The drug has been shown to be effective in improving blood pressure control, reducing edema, and increasing urine output in patients with various conditions 3, 4, 6, 7

Dosage and Administration

• The recommended dose of metolazone varies depending on the condition being treated, but typical doses range from 2.5 to 20 mg per day 4, 6
• In patients with refractory heart failure, a low starting dose of metolazone (<5 mg) is often used in combination with a loop diuretic 4, 6
• The absorption of metolazone may be reduced in patients with heart failure, and the drug may produce a diuretic response despite a low glomerular filtration rate 4

Adverse Effects

• Common adverse effects of metolazone include:
  • Hypokalemia (low potassium levels) 3, 4, 5, 6, 7
  • Hyponatremia (low sodium levels) 5, 6
  • Hypochloraemia (low chloride levels) 7
  • Encephalopathy (brain dysfunction) 7
  • Azotaemia (elevated blood urea nitrogen and creatinine levels) 7
• These adverse effects can be minimized by monitoring electrolyte levels and adjusting the dose of metolazone as needed 3, 4, 6, 7