Inhaled VIP Peptide Selectively Relaxed Lung Blood Vessels in Pulmonary Hypertension Patients
A single inhaled dose of aviptadil (VIP) selectively dilated pulmonary blood vessels and reduced right heart strain in 20 pulmonary hypertension patients without side effects or systemic blood pressure drops.
Quick Facts
What This Study Found
A single inhaled dose of aviptadil (100 μg), a synthetic form of vasoactive intestinal peptide (VIP), caused selective pulmonary vasodilation in patients with chronic pulmonary hypertension. The peptide improved stroke volume and mixed venous oxygen saturation — indicating reduced strain on the right ventricle — without affecting systemic blood pressure. Six of 20 patients (30%) achieved a clinically meaningful >20% reduction in pulmonary vascular resistance.
In patients with significant lung disease, aviptadil also tended to improve oxygenation. The effect was modest and temporary (as expected from a single dose), but no side effects were reported. The selective pulmonary vasodilation means the drug targeted the lung blood vessels specifically without dropping blood pressure throughout the rest of the body.
Key Numbers
n=20 · single 100 μg inhaled dose · 6/20 (30%) achieved >20% PVR reduction · improved stroke volume · improved mixed venous O2 saturation · no systemic BP drop · zero side effects
How They Did This
Open-label study in 20 patients with chronic pulmonary hypertension (9 PAH, 8 PH with lung disease, 3 chronic thromboembolic PH). During right-heart catheterization, patients inhaled a single 100 μg dose of aviptadil aerosol. Hemodynamic parameters (pulmonary vascular resistance, stroke volume, cardiac output) and blood gases (arterial and mixed venous oxygen saturation) were measured before and after inhalation.
Why This Research Matters
Pulmonary hypertension is a devastating condition where high pressure in the lung arteries forces the right side of the heart to work progressively harder until it fails. Current treatments help but don't cure the disease. VIP is naturally deficient in patients with idiopathic pulmonary arterial hypertension, making replacement therapy a logical approach. The fact that inhaled aviptadil selectively dilated lung vessels without systemic side effects is promising — inhaled delivery keeps the drug where it's needed most.
The Bigger Picture
Pulmonary hypertension treatment has advanced significantly with drugs like sildenafil, bosentan, and prostacyclin analogs, but many patients remain inadequately treated. VIP represents a different mechanism — replacing a peptide that is naturally deficient in PAH patients. The inhaled route is attractive because it concentrates the drug in the lungs and avoids systemic side effects. Aviptadil has since been investigated in other lung conditions including COVID-19-related respiratory failure.
What This Study Doesn't Tell Us
This was an uncontrolled, open-label study with no placebo group, so the effects could partly reflect the natural variability of hemodynamics during catheterization. The single-dose design only assessed acute effects — chronic dosing may produce different results. The 100 μg dose may have been suboptimal (the authors suggest higher doses should be tested). Only 20 patients were studied across three different PH subtypes, limiting subgroup analysis. The temporary nature of the effect means multiple daily doses would likely be needed for clinical use.
Questions This Raises
- ?Would higher doses or chronic inhaled aviptadil treatment produce larger and sustained hemodynamic improvements?
- ?How does inhaled aviptadil compare to existing inhaled pulmonary vasodilators like iloprost or nitric oxide?
- ?Could VIP replacement therapy alter disease progression in idiopathic PAH, not just acutely improve hemodynamics?
Trust & Context
- Key Stat:
- Selective vasodilation Inhaled aviptadil dilated pulmonary blood vessels without dropping systemic blood pressure — targeting therapy exactly where it's needed
- Evidence Grade:
- This is an uncontrolled, open-label study with 20 patients testing a single dose. While the hemodynamic measurements are objective (right-heart catheterization), the 'Preliminary' grade reflects the small size, lack of placebo control, and single-dose acute design.
- Study Age:
- Published in 2008, this was an early proof-of-concept study for inhaled VIP in pulmonary hypertension. Aviptadil has since been investigated further, including for COVID-19-related respiratory failure, though it has not yet become a standard PH treatment.
- Original Title:
- Inhalation of vasoactive intestinal peptide in pulmonary hypertension.
- Published In:
- The European respiratory journal, 32(5), 1289-94 (2008)
- Authors:
- Leuchte, H H, Baezner, C, Baumgartner, R A, Bevec, D, Bacher, G, Neurohr, C, Behr, J
- Database ID:
- RPEP-01375
Evidence Hierarchy
Frequently Asked Questions
What is VIP and why is it relevant to pulmonary hypertension?
Vasoactive intestinal peptide (VIP) is a natural peptide that relaxes blood vessels and reduces inflammation. In patients with idiopathic pulmonary arterial hypertension, VIP levels are abnormally low — which may contribute to the excessive blood vessel constriction in the lungs. Replacing VIP through inhalation delivers it directly to the pulmonary blood vessels, where the deficiency exists.
Why is 'selective pulmonary vasodilation' important?
In pulmonary hypertension, the goal is to lower pressure in the lung arteries specifically — not throughout the whole body. Many blood pressure drugs lower pressure everywhere, which can cause dangerous drops in systemic blood pressure, dizziness, and fainting. Because aviptadil was inhaled, it concentrated in the lungs and relaxed those blood vessels while leaving systemic blood pressure unchanged. This is the ideal profile for a PH drug.
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Cite This Study
https://rethinkpeptides.com/research/RPEP-01375APA
Leuchte, H H; Baezner, C; Baumgartner, R A; Bevec, D; Bacher, G; Neurohr, C; Behr, J. (2008). Inhalation of vasoactive intestinal peptide in pulmonary hypertension.. The European respiratory journal, 32(5), 1289-94. https://doi.org/10.1183/09031936.00050008
MLA
Leuchte, H H, et al. "Inhalation of vasoactive intestinal peptide in pulmonary hypertension.." The European respiratory journal, 2008. https://doi.org/10.1183/09031936.00050008
RethinkPeptides
RethinkPeptides Research Database. "Inhalation of vasoactive intestinal peptide in pulmonary hyp..." RPEP-01375. Retrieved from https://rethinkpeptides.com/research/leuchte-2008-inhalation-of-vasoactive-intestinal
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Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.