Metolazone Dosage and Usage for Hypertension and Edema
For hypertension, metolazone should be initiated at 2.5 to 5 mg once daily, while for edema management in heart failure, the recommended dosage is 5 to 20 mg once daily. 1
Dosing for Hypertension
- Initial dosage for mild to moderate essential hypertension: 2.5 to 5 mg once daily 1
- Lower starting dose (0.5 mg) may be appropriate for some patients, as studies show 51-58% of patients achieve blood pressure control even at this lower dose 2
- The antihypertensive effect may take 3-6 weeks to fully manifest, requiring patience during initial therapy 1
- Thiazide-like diuretics such as metolazone are recommended as one of the first-line treatments for hypertension, often in combination with other agents 3
Dosing for Edema Management
- For edema of cardiac failure: 5 to 20 mg once daily 1
- For edema of renal disease: 5 to 20 mg once daily 1
- Diuretic effect typically begins within one hour and persists for 24 hours or longer 1
- For patients with paroxysmal nocturnal dyspnea, a larger dose may be needed to ensure full 24-hour diuretic effect 1
Combination Therapy in Heart Failure
- For refractory edema unresponsive to loop diuretics alone, metolazone may be added to enhance diuresis 3
- When combining with loop diuretics, a lower starting dose of metolazone (2.5 mg) is recommended 4
- Metolazone should be administered 30 minutes before loop diuretics for optimal synergistic effect through sequential nephron blockade 5
- Short-term use (2-3 days) is typically sufficient when used in combination therapy for heart failure 5
Monitoring and Precautions
- Regular monitoring of electrolytes is essential, as severe electrolyte disturbances can occur, particularly when combined with loop diuretics 6
- Hyponatremia, hypochloremia, hypokalemia, and metabolic alkalosis are common adverse effects requiring vigilance 6
- Renal function should be monitored, as transient increases in serum creatinine may occur, especially in patients with pre-existing renal insufficiency 7
- Target weight reduction of 0.5-1.0 kg per day during therapy 5
Special Considerations
- In patients with severe renal insufficiency, metolazone maintains efficacy despite low glomerular filtration rate, but requires careful monitoring 4, 7
- Combination of metolazone with furosemide can produce dramatic diuresis in patients resistant to either diuretic alone 7, 8
- For patients with heart failure and hypertension, metolazone can serve dual purposes of blood pressure control and edema management 3
- Hospital admission may be warranted when initiating combination therapy in high-risk patients (elderly, severe heart failure, baseline renal dysfunction) 5
Titration and Maintenance
- Dosage should be titrated to achieve the desired therapeutic response while using the minimal effective dose 1
- Once the target effect is achieved, consider dose reduction to minimize adverse effects 1
- For long-term management, the lowest effective dose should be maintained to prevent recurrence of symptoms 3