Is furosemide (Lasix) contraindicated in patients with pulmonary hypertension?

Furosemide is NOT Contraindicated in Pulmonary Hypertension

Furosemide is recommended for patients with pulmonary hypertension who have signs of right ventricular failure and fluid retention, and should be used judiciously as part of supportive therapy. 1

Evidence-Based Recommendations

When Furosemide IS Indicated

Diuretic treatment is indicated (Class I recommendation, Level C evidence) in pulmonary arterial hypertension patients with signs of right ventricular failure and fluid retention. 1 This represents the clearest guideline statement supporting furosemide use in this population.

• Loop diuretics including furosemide are standard supportive therapy for managing volume overload in pulmonary hypertension patients with decompensated right heart failure 1
• The European Society of Cardiology/European Respiratory Society guidelines explicitly recommend diuretics as part of the supportive therapy algorithm for pulmonary hypertension 1

Critical Context: Acute Heart Failure with Pulmonary Edema

For patients with acute heart failure syndromes causing pulmonary edema (distinct from primary pulmonary hypertension), furosemide combined with nitrate therapy receives a Level B recommendation for moderate-to-severe pulmonary edema 1

• However, aggressive diuretic monotherapy is unlikely to prevent intubation compared to aggressive nitrate monotherapy 1
• Diuretics should be administered judiciously given potential associations with worsening renal function, which correlates with long-term mortality 1

Important Hemodynamic Considerations

Transient Adverse Effects

Furosemide can cause transient worsening of hemodynamics for 1-2 hours after administration, including increased systemic vascular resistance, increased left ventricular filling pressures, and decreased stroke volume 1

• These effects were documented in patients with advanced chronic heart failure, though generalizability to acute settings remains uncertain 1
• Research shows furosemide may increase arterial angiotensin-II plasma levels, potentially through renin-angiotensin system activation 2

Pulmonary Vascular Effects

Despite reducing central pressures, furosemide does not immediately reduce pulmonary blood volume or pulmonary extravascular fluid volume in patients with postcapillary pulmonary hypertension 3

• The pulmonary extravascular space is relatively resistant to early decreases in pulmonary capillary pressure induced acutely 3
• In secondary pulmonary hypertension, torasemide may have more favorable hemodynamic effects than furosemide, increasing cardiac output without significantly raising angiotensin-II levels 2

Specific Contraindications to Consider

Absolute Contraindications (Not PH-Specific)

Furosemide should be avoided in patients with 4:

• Pheochromocytoma (can precipitate hypertensive crisis) 5
• Acute kidney disease with anuria
• Severe electrolyte depletion

Relative Contraindications in PH Context

Avoid aggressive diuresis in patients with pulmonary hypertension who are preload-dependent, as excessive volume depletion can compromise right ventricular filling and cardiac output 1

• Patients with severe right ventricular dysfunction require careful volume management 1
• Monitor for signs of inadequate preload: hypotension, rising lactate, decreased urine output 1

Clinical Algorithm for Furosemide Use in PH

Step 1: Assess Volume Status

• If signs of right heart failure with fluid retention present (peripheral edema, ascites, elevated jugular venous pressure): Furosemide is indicated 1
• If euvolemic or hypovolemic: Avoid diuretics 1

Step 2: Dosing Strategy

• Start with conservative doses and titrate based on response 1
• Monitor electrolytes, renal function, and volume status closely 1
• Provide adequate potassium supplementation to prevent hypokalemia and metabolic alkalosis, which can exacerbate CO2 retention 1

Step 3: Combination Therapy

• In acute pulmonary edema settings, combine with nitrate therapy rather than using as monotherapy 1
• Continue PAH-specific therapies (phosphodiesterase-5 inhibitors, endothelin receptor antagonists, prostanoids) unless contraindicated 1

Step 4: Monitoring

• Watch for worsening renal function, which predicts poor long-term outcomes 1
• Assess for signs of excessive diuresis: hypotension, prerenal azotemia, electrolyte abnormalities 1
• Monitor for transient hemodynamic worsening in the first 1-2 hours after IV administration 1

Common Pitfalls to Avoid

Do not withhold furosemide from volume-overloaded pulmonary hypertension patients based on concerns about pulmonary hypertension itself - the guidelines explicitly support its use in this context 1

Do not use furosemide as monotherapy for acute pulmonary edema - combination with nitrates is superior 1

Do not assume furosemide will rapidly improve dyspnea in hypertensive pulmonary edema - one randomized trial showed no difference in dyspnea scores at 1 hour compared to placebo when blood pressure was adequately controlled 6

Avoid in patients with chronic systolic heart failure and pulmonary hypertension who are receiving prostacyclin therapy - epoprostenol is contraindicated in this population due to increased mortality risk 1