Diuretic Therapy

Initiation and Dosing

• The American College of Cardiology recommends starting continuous infusion at 10-40 mg per hour after initial bolus, with a maximum single IV bolus dose of 160-200 mg, and adding thiazide diuretic or metolazone for sequential nephron blockade 1
• Initial IV furosemide dosing should be 20-40 mg IV bolus for diuretic-naïve patients, and at least equal to the previous oral dose for those already on diuretics, with higher doses for patients with chronic diuretic use or renal dysfunction, according to the European Heart Journal 2
• The initial dose for IV administration is 20-40 mg bolus, and for oral administration, the dose is 20-40 mg once or twice daily, with a maximum of 600 mg/day 3, 4

Alternative Loop Diuretics

• The American College of Cardiology recommends alternative loop diuretics with equivalent doses, including Bumetanide: 1 mg IV bolus then 0.5-2 mg/hour infusion, and Torsemide: 20 mg IV bolus then 5-20 mg/hour infusion 1
• Maximum doses for loop diuretics are as follows:

5

• Loop diuretics are the cornerstone first-line therapy for acute heart failure exacerbations with congestion, regardless of renal function, as recommended by the European Society of Cardiology 3, 6, 2

Combination Therapy

• Thiazide diuretics should be added when there is an inadequate response to optimized loop diuretic therapy, signs of diuretic resistance, or a need for enhanced natriuresis in severe volume overload, as suggested by the European Journal of Heart Failure 3, 6
• The first choice thiazide for patients with chronic heart and kidney failure is metolazone, with a dosage of 5-10 mg once daily, as recommended by the European Society of Cardiology 6
• Combination therapy with spironolactone and furosemide can be used in patients with recurrent severe ascites or when faster diuresis is needed, as recommended by the American Heart Association and the American Gastroenterological Association 7, 8

Monitoring and Adjustments

• Electrolytes, particularly potassium, sodium, and magnesium, should be monitored, as well as renal function, fluid status, and blood pressure, to ensure safe and effective diuretic therapy, as recommended by the European Society of Cardiology 6
• Essential monitoring parameters include symptoms, urine output, renal function, electrolytes (especially potassium and sodium), and daily weight measurements, as recommended by the European Society of Cardiology and the American Heart Association 2, 9
• Warning signs for dehydration or worsening renal function include a creatinine increase >50% from baseline or >3.0 mg/dL, potassium <3.5 or >5.5 mmol/L, and signs of dehydration, prompting immediate reassessment and potential dose reduction 5

Special Considerations

• Thiazide monotherapy should be avoided in acute heart failure with renal dysfunction, and always used in combination with loop diuretics, as recommended by the European Society of Cardiology 3, 6
• Relative contraindications for furosemide include hypotension (SBP <90 mmHg), severe hyponatremia, and acidosis, as listed by the European Society of Cardiology 3
• The American College of Cardiology recommends adding a combination of hydralazine and isosorbide dinitrate to improve outcomes for African American patients with heart failure who are already taking furosemide, with a Class I, Level of Evidence B rating 1, 10, 11

Guideline Recommendations

• The following table lists the recommendations from various societies: