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.
Phase:
Phase 1/Phase 2
Details
Lead Sponsor:
National Institute of Allergy and Infectious Diseases (NIAID)