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Edema, PulmonaryPhase 2NCT03686813

Sildenafil for Swimming-Induced Pulmonary Edema (SIPE) Prevention

A Phase 2 study testing Sildenafil Citrate in people with Edema, Pulmonary and Immersion, run by Duke University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This trial is testing the effectiveness of a single oral dose of sildenafil (50 mg) taken 1 hour before a provocative event on the subsequent development of swimming-induced pulmonary edema. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Edema, Pulmonary, Immersion, Diving
What is being tested?
Sildenafil Citrate
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
18 participants
Where
1 siteUnited States
Study dates
15 Jul 2019to 29 Oct 2021
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy volunteers between 18 and 45 years
  • History of swimming-induced pulmonary edema

Who cannot join

  • Pregnant women
  • Significant heart valve disease
  • Cardiomyopathy
  • Uncontrolled hypertension
  • Coronary artery disease
  • Obstructive lung disease
Show all 9Show fewer
  • VO2max <25 mL/kg as estimated by the University of Houston Non-Exercise Test
  • Previous adverse reaction to sildenafil
  • Use of antihypertensives or other drugs that are known to interact adversely with sildenafil (e.g. nitrates, alpha adrenergic blockers)

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Duke University Medical Center

    Durham, North Carolina, 27710

Other trials in United States

About this study

Official title: Sildenafil for Prevention of Swimming-Induced Pulmonary Edema (SIPE)

This trial is testing the effectiveness of a single oral dose of sildenafil (50 mg) taken 1 hour before a provocative event on the subsequent development of swimming-induced pulmonary edema.

Read the detailed description

Immersion pulmonary edema (also known as swimming-induced pulmonary edema, SIPE) is a condition in which the lungs fill with fluid (pulmonary edema) during a dive or vigorous swim, causing cough with bloody sputum, shortness of breath and reduced blood oxygen levels. In the Navy this usually occurs in young, healthy individuals such as SEAL and Special Warfare Combatant-Craft trainees. SIPE generally resolves spontaneously within 24 hours but it can be fatal. It is believed that SIPE is responsible for some deaths in civilians during triathlons. This proposal aims to test a drug to prevent SIPE.

Depending upon severity, the prevalence of SIPE is reported in up to 60% during 2.4-3.6 km open sea swimming trials in the Israel Defense Force. In SEAL training in the US approximately 40 cases per year (around 3%) have been reported, more commonly during winter, when it is observed in up to 5% of trainees. Return to duty time can be up to 7 days. SIPE also affects other groups of highly fit individuals such as triathletes. In susceptible individuals it tends to recur, thus a preventive medicine would be useful for both Navy SEALs and civilians.

The aim of this study will be to provide the Navy an FDA-approved drug that can be used to prevent SIPE. The investigators hypothesize that sildenafil administration to SIPE-susceptible individuals one hour before a swim in cold water will reduce or eliminate the risk of SIPE. The method to be used to test this hypothesis will be a 40-minute period of exercise immersed to the neck in 20°C water, a test that results in SIPE symptoms in the majority of susceptible individuals. The investigators plan to study 20 individuals who have previously experienced SIPE. Each volunteer will be tested twice. Either sildenafil or an inactive drug (placebo) administered in random order will be given prior to each exercise. For each participant exercise periods will be performed at least 7 days apart. The identity of the drug and placebo will be concealed from the investigators and the volunteers until the end of the study. The number of instances in which SIPE manifestations after sildenafil and placebo will then be compared.

Availability of a drug that can prevent SIPE would provide the Navy with a useful tool that could be administered to SEALs who have experienced SIPE prior to critical missions. It would also be useful for civilians who have experienced SIPE but wish to continue with the precipitating exercise such as swimming or competing in triathlons, and also for patients with heart failure for whom swimming induces shortness of breath or pulmonary edema.

Being tested
Sildenafil Citrate, Placebo Oral Tablet
Medical subject headings
Pulmonary Edema

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Sildenafil CitrateDrug

    Also called Viagra, Revatio

    Oral sildenafil, 50 mg

  • Placebo Oral TabletDrug

    Placebo

Study groups in NCT03686813
Study groupRoleWhat they receive
PlaceboPlacebo comparatorEach participant will be studied with active drug and placebo.
Receives: Drug: Placebo Oral Tablet
SildenafilActive comparatorSildenafil 50 mg orally one hour (once) before immersed exercise
Receives: Drug: Sildenafil Citrate

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants With Pulmonary Edema

    One or more of: hypoxemia, productive cough, pulmonary edema on chest radiograph, wheezing on chest auscultation.

    Measured: During or immediately after exercise in cold water, approximately one hour and 40 minutes

Secondary outcomes (4)
  1. Number of Participants With Dyspnea Leading to Voluntary Premature Cessation of Exercise

    Voluntary premature cessation of exercise due to shortness of breath.

    Measured: During or immediately after exercise in cold water, approximately one hour and 40 minutes

  2. Number of Participants With Post-exercise 10% Decrease in Forced Vital Capacity (FVC) or Forced Expiratory Volume in One Second (FEV1) as Measured by Spirometry

    Post-exercise 10% decrease in forced vital capacity (FVC) or forced expiratory volume in one second (FEV1).

    Measured: Immediately after exercise in cold water, approximately one hour and 40 minutes

  3. Number of Participants With "Comet Tails" Seen on Ultrasound of the Lungs

    A "comet tail" artefact is a short path reverberation artefact that weakens with each reverberation, resulting in a vertical echogenic artefact that rapidly fades as it continues in to the ultrasound image.

    Measured: Immediately after exercise in cold water, approximately one hour and 40 minutes

  4. Number of Participants Who Found the Exercise Easiest When Given Sildenafil Citrate Versus When Given Placebo

    Measured: Immediately after exercise in cold water, approximately one hour and 40 minutes

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted27 Sep 2018
  2. Study start15 Jul 2019
  3. Primary completion29 Oct 2021
  4. Study completion29 Oct 2021

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Crossover
Model description
Double blind, randomized
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
18 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03686813
Sponsor's protocol ID
Pro00100971
Status last verified
Oct 2022
First submitted
24 Sep 2018
Last updated
22 Nov 2022
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Undecided: Data will be published in the open literature

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Sildenafil Citrate in people with Edema, Pulmonary and Immersion, run by Duke University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 22 Nov 2022. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 22 Nov 2022). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Pulmonary Edema (time frame: During or immediately after exercise in cold water, approximately one hour and 40 minutes). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Nov 2022.

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