Aviptadil

Summary

Aviptadil is a synthetic analogue of vasoactive intestinal peptide (VIP) developed as an investigational drug. It has been explored for several pulmonary and vascular conditions, including pulmonary arterial hypertension, acute respiratory distress syndrome (ARDS), and COVID‑19‑related hypoxaemic respiratory failure, as well as in early studies for erectile dysfunction. The compound is administered by inhalation, intravenous infusion, or subcutaneous injection, but it remains unapproved for any indication.

Mechanism of Action

Aviptadil mimics VIP and activates the VPAC1 and VPAC2 G‑protein‑coupled receptors on airway smooth muscle, endothelial cells, and immune cells. Receptor activation raises intracellular cAMP, producing bronchodilation, vasodilation, and inhibition of cytokine release. In the erectile‑dysfunction formulation, concurrent phentolamine blocks α‑adrenergic receptors, enhancing penile blood flow. The combined actions are thought to reduce pulmonary vascular resistance, protect alveolar epithelium, and modulate inflammatory pathways.

What the Research Shows

Early clinical work described an injectable VIP/phentolamine combination for erectile dysfunction, with regulatory filings in several countries but later clinical holds due to safety concerns. Pre‑clinical data highlighted VIP’s anti‑inflammatory properties, prompting repurposing proposals for COVID‑19. A 2025 systematic review and meta‑analysis of nine ARDS studies (665 patients) found that aviptadil improved oxygenation and lowered inflammatory markers in case series, but pooled randomized data showed no significant survival advantage (OR 1.01, p = 0.93). A 2008 review listed inhaled aviptadil as a candidate for pulmonary arterial hypertension. The 2023 TESICO trial evaluated intravenous aviptadil plus remdesivir in hypoxaemic COVID‑19 patients, but the abstract provides no efficacy results, only that the trial was conducted. Overall, evidence consists of early-phase studies, case series, and limited randomized trials, with mixed outcomes.

Reported Benefits

Aviptadil’s activation of VPAC receptors can produce bronchodilation and vasodilation, which may improve pulmonary hemodynamics in conditions like PAH. Case series in ARDS report better oxygenation and reduced inflammatory biomarkers, suggesting a cytoprotective effect on lung tissue. In the erectile‑dysfunction formulation, phentolamine‑mediated α‑blockade may augment penile blood flow. These physiological actions constitute the primary rationale for its investigational use.

Limitations of the Evidence

High‑quality randomized evidence is scarce; the ARDS meta‑analysis found no survival benefit, and the COVID‑19 trial’s outcomes remain unpublished. Sample sizes are small, and many reports are limited to case series. Safety concerns—including animal carcinogenicity signals and FDA‑mandated clinical holds—have constrained development. Consequently, the therapeutic value of aviptadil remains uncertain pending larger, well‑controlled studies.

Safety Considerations

Pre‑clinical studies raised concerns about brown adipose tissue proliferation and carcinogenicity in rodents, although regulators judged the risk low for humans. The FDA placed a partial clinical hold in 2000 due to safety issues with a related phentolamine product. Reported adverse‑event profiles in COVID‑19 trials are described as “peculiar,” suggesting the need for close monitoring of hypotension, vascular effects, and potential immune modulation. No definitive human safety data are available, and the compound remains investigational.

How It Is Administered

Aviptadil can be delivered by inhalation (investigated for pulmonary arterial hypertension), intravenous infusion (used in COVID‑19 trials), or subcutaneous injection (available in an autoinjector device for self‑administration in early erectile‑dysfunction studies). Formulations are peptide solutions; dosing regimens have not been established for any approved indication.

Routes of Administration

Goals & Uses

• COVID‑19 severe pneumoniaInfectiousModerate
• Erectile dysfunctionSexual HealthLow
• Sarcoidosis-related respiratory failureRespiratoryLow
• COVID-19-associated respiratory failureInfectious Disease / RespiratoryModerate
• Cytokine storm suppressionImmunomodulationModerate
• Pulmonary arterial hypertension (PAH)Cardiovascular / PulmonaryLow
• Acute Respiratory Distress Syndrome (ARDS)RespiratoryModerate
• Pulmonary hypertensionCardiovascularLow

Contraindications

• PregnancyPopulationModeratePotential fetal risk or insufficient safety data
• Known hypersensitivity to aviptadil or any peptide excipientsAllergyHigh
• Hypersensitivity to VIP or aviptadilAllergyHigh
• Uncontrolled cardiac arrhythmiasCardiovascularModerate
• Severe hypotension (SBP <90 mmHg)HemodynamicModerate
• Severe hypotensionCardiovascularHigh

Adverse Effects

• Injection site reactionsLocalUncommon
• HeadacheNeurologicUncommonPain in the head or upper neck
• HypotensionCardiovascularCommonLow blood pressure
• FlushingVascularCommonWarmth and redness of the skin
• TachycardiaCardiovascularUncommonAbnormally fast heart rate
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit
• DiarrheaGastrointestinalUncommonLoose or frequent stools

Drug Interactions

• Antihypertensive agentsModerate
• Other vasodilators (e.g., nitroglycerin, ACE inhibitors)Moderate
• CYP‑metabolized drugsLow
• CorticosteroidsLow
• Vasopressors (e.g., norepinephrine)Low
• Phosphodiesterase-5 inhibitors (e.g., sildenafil)High

Population Constraints

• PregnancyReproductive SafetyRelative
• Renal impairmentOrgan ImpairmentRelative
• Pediatric patientsAgeRelative
• Pediatrics (<12 years)AgeRelative
• Patients with pre-existing severe hypotensionCardiovascularRelative
• Pregnant womenReproductiveRelative
• Elderly patients (≥65 years)Age RelatedRelative

Regulatory Status

• European UnionUnapprovedNo marketing authorization
• United StatesInvestigationalIND status; not FDA‑approved
• United KingdomUnapprovedNot licensed for clinical use

Received FDA Breakthrough Therapy Designation for treatment of COVID-19-associated respiratory failure. Not currently FDA-approved for any indication. Studied under Emergency Use Authorization context during COVID-19 pandemic. Orphan drug designation in EU for pulmonary arterial hypertension.

Evidence & Sources

• Aviptadil (Senatek)
  Journal ArticleModerateKeijzers GB2001-01-01T00:00:00.000000Z
• Anticipated pharmacological role of Aviptadil on COVID-19
  Journal ArticleModerateMukherjee T, et al.2022-01-01T00:00:00.000000Z
• Aviptadil Therapy in Acute Respiratory Distress Syndrome Patients: A Systematic Review and Meta-analysis
  Journal ArticleModerateUdupa AA, et al.2025-01-01T00:00:00.000000Z
• Pulmonary arterial hypertension: on the way to a manageable disease
  Journal ArticleModerateMucke HA2008-01-01T00:00:00.000000Z
• Intravenous aviptadil and remdesivir for treatment of COVID-19-associated hypoxaemic respiratory failure in the USA (TESICO): a randomised, placebo-controlled trial
  Journal ArticleModerateBrown SM, et al.2023-01-01T00:00:00.000000Z
• Novel Targets of Drug Treatment for Pulmonary Hypertension
  Journal ArticleModerateHu J, et al.2015-01-01T00:00:00.000000Z

Frequently Asked Questions