Nontuberculous Mycobacterial Infection Clinical Trial
Official title:
Sildenafil in Patients With Pulmonary Nontuberculous Mycobacterial Infection
Background:
- Pulmonary nontuberculous mycobacterial (PNTM) infection is caused by a common type of
bacteria in the environment. Although PNTM infection is most common in people with lung
diseases, it can also affect healthy people. It can be difficult to treat, and affects
parts of the body other than the lungs. For example, PNTM may affect the cilia, the
hair-like structures inside the nose and lungs that help move dirt and debris out of the
body.
- Ciliary beat frequency (CBF) is a measurement of how fast cilia move. People with PNTM
infection have a lower CBF than healthy people. Nitric oxide (NO) is a gas in the body
that may affect CBF. People with PNTM infection produce lower amounts of NO in their
noses than healthy people. Researchers want to see if a drug called sildenafil can
increase NO production and CBF. If sildenafil can improve these measurements, it may be
a useful treatment for PNTM infection.
Objectives:
- To study the effect of sildenafil on CBF and NO levels in people with PNTM infection.
Eligibility:
- Individuals at least 18 years of age who have PNTM infection.
- Participants must be enrolled in a related National Institutes of Health study on
bacterial infections. The study is Natural History, Genetics, Phenotype and Treatment of
Mycobacterial Infections.
Design:
- Participants will be screened with a physical exam and medical history. They will also
have heart and lung function tests, as well as tests of NO production in the nose. They
will provide samples of sputum and cells from inside the nose.
- Before the first study visit, participants will collect sputum samples for 24 hours.
They will bring the samples to the study visit.
- At the first study visit, participants will have heart and lung function tests, as well
as tests of NO production in the nose. They will provide blood, urine, sputum, and nasal
cell samples. They will also receive sildenafil tablets to take at home.
- Participants will take sildenafil tablets three times a day.
- The second study visit will be 7 days after the first one. The tests from the first
visit will be repeated. Participants will receive more sildenafil tablets to take on the
same schedule as before.
- The third and final study visit will be 30 days after the first one. The tests from the
first visit will be repeated. Participants will stop taking sildenafil at this visit.
- A follow-up phone call will be made about 2 weeks after the final study visit. This call
will ask questions about quality of life and any symptoms or side effects of the study.
Pulmonary nontuberculous mycobacterial (PNTM) infection has increased over the past several
decades, especially in older women. No consistent immunological abnormalities have been found
despite extensive investigation. In cystic fibrosis and primary ciliary dyskinesia,
mucociliary dysfunction predisposes individuals to high rates of PNTM disease that increases
markedly with age.
We studied the respiratory biology of subjects with PNTM and healthy controls and found
decreased levels of nasal nitric oxide (nNO) in vivo. Ex vivo analysis of ciliated
respiratory epithelium from subjects with PNTM demonstrated an abnormally low resting ciliary
beat frequency (CBF) and an abnormal response to toll-like receptor ([TLR]2,TLR3, TLR5,
TLR7/8, and TLR9) agonists, compared with respiratory samples from healthy controls. The low
CBF response was normalized ex vivo by augmenting the nitricoxide-cyclic guanosine
monophosphate pathway; this supplementation had no appreciable effect on the differences in
TLR responses observed in subjects with PNTM and healthy controls. The reduced CBF and nNO
levels in these subjects reveal possible mechanisms of susceptibility to respiratory
infections, as well as possible avenues of directed investigation and therapy.
This is an open-label, interventional study evaluating the effects of sildenafil on CBF in
subjects with PNTM infection. The study will also measure the effects of sildenafil on nNO,
and it will evaluate the quality of life, exertional capacity, pulmonary function, lower
airway microbiology, inflammatory markers, and the safety and tolerability of sildenafil
treatment in this population.
The first 5 subjects will receive an oral bolus of sildenafil (40 mg) on day 0 followed by an
oral dose of 20 mg 3 times a day (tid) starting on day 1 for approximately 6 days until the
study visit on day 7. The remaining 5 subjects will receive an oral dose of sildenafil (20
mg) tid on day 0 for approximately 1 week until the study visit on day 7. Subsequently, the
dose will be increased for all subjects to 40 mg tid and will be administered for another 3
weeks until the study visit on day 30 (4 weeks in total). Administering an initial oral bolus
will help us examine sildenafil s immediate effects on CBF and safety parameters. The dosing
necessary to modulate CBF in this subject population is not yet known, thus, we feel that
undertaking a dose-ranging study will allow a thorough evaluation of sildenafil s effects on
CBF.
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| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT00368446 -
Genetic Disorders of Mucociliary Clearance in Nontuberculous Mycobacterial Lung Disease
|