Sildenafil to Increase Exercise Capacity in Individuals With Idiopathic Pulmonary Fibrosis and Pulmonary Hypertension

Sildenafil Treatment in Patients With Idiopathic Pulmonary Fibrosis and Pulmonary Hypertension - a Pilot Cross-over Study

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease that affects an individual's ability to breathe. Currently, no medications can reverse the damage to the lungs caused by IPF, but individuals are encouraged to engage in moderate exercise to strengthen lung function. This study will evaluate the effectiveness of sildenafil at improving exercise tolerance and breathing difficulties in individuals with IPF.

Study Overview

• Status: Completed
• Conditions: Pulmonary Fibrosis; Hypertension, Pulmonary
• Intervention / Treatment: Drug: Sildenafil (50 mg)

Detailed Description

IPF is a disease that damages the air sacs in the lungs and leads to widespread and permanent scarring of lung tissue. Individuals with IPF may experience breathing difficulties, cough, chest pain, and a decreased exercise capacity. There is no cure for this disease, and individuals usually die within 3 to 5 years. It is recommended that individuals with IPF engage in moderate exercise, as this can help maintain strength and improve lung function. Many individuals with IPF also suffer from pulmonary hypertension, which is high blood pressure in the arteries leading to the lungs. Sildenafil, a medication currently used to treat pulmonary hypertension, increases blood flow to the lungs and enhances gas exchange within the lungs. The purpose of this study is to evaluate the effectiveness of sildenafil at improving exercise tolerance and breathing difficulties in individuals with IPF and pulmonary hypertension.

This 3-week study will enroll individuals with IPF and pulmonary hypertension. Study visits will occur at baseline, and Weeks 1 and 2. At the baseline visit, participants will perform a 6-minute walk test, which will measure the distance walked in a 6-minute period. Oxygen levels will be measured prior to and during the test, and standardized questionnaires will be completed to assess breathing difficulties. A second 6-minute walk test will be performed 1 hour following the first test. At the Week 1 visit, participants will be randomly assigned to receive a single dose of either 50 mg of sildenafil or placebo. One hour after receiving the medication, they will complete another 6-minute walk test. The Week 2 visit will be identical to the Week 1 visit, except participants who received sildenafil at Week 1 will receive placebo at Week 2, and vice versa.

• Study Type: Interventional
• Enrollment (Anticipated): 20
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90095
      • UCLA Pulmonary Outpatient Clinic,

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• IPF, diagnosed according to the American Thoracic Society (ATS) and European Respiratory Society (ERS) consensus statement (with or without surgical lung biopsy)
• Pulmonary hypertension, defined as mean pulmonary artery pressure (MPAP) greater than or equal to 25 mm Hg by right heart catheterization (RHC)

Exclusion Criteria:

• Interstitial lung disease due to conditions other than IPF
• Recent lung or upper respiratory tract infection within 4 weeks of study entry
• Acute or chronic impairment other than dyspnea (e.g., angina pectoris, intermittent claudication) limiting the ability to comply with study requirements (e.g., 6-minute walk test)
• Known hypersensitivity to sildenafil
• Known or suspected coronary artery disease (CAD)
• Unstable angina
• Nitrate use
• Known or suspected aortic stenosis (AS)
• Known or suspected heart attack, stroke, or life-threatening arrythmias within 1 month of study entry
• Severe chronic heart failure, defined as New York Heart Association (NYHA) class III/IV and/or left ventricular ejection fraction less than 25%
• Known penile deformities
• Known kidney or liver dysfunction
• Uncontrolled diabetes (blood glucose less than 60 mg/dl or greater than 300 mg/dl)
• Severe serum sodium abnormalities (serum sodium less than 130 mEq/L or greater than 150 mEq/L)
• Condition that may predispose participant to priapism (e.g., sickle cell anemia, multiple myeloma, leukemia)
• Retinitis pigmentosa
• Known or suspected idiopathic hypertrophic subaortic stenosis (IHSS)
• Low blood pressure (systolic blood pressure [SBP] less than 100 mm Hg or diastolic blood pressure [DBP] less than 50 mm Hg)
• Uncontrolled systemic high blood pressure (SBP greater than 180 mm Hg or DBP greater than 100 mm Hg)
• Cardiopulmonary rehabilitation program started within 8 weeks of study entry or likely to start prior to the conclusion of the study
• Treatment with an endothelin receptor antagonist, iloprost, epoprostenol, inhibitors of CYP3A4 (e.g., cimetidine, erythromycin, ketoconazole, itraconazole, mibefradil), protease inhibitors (e.g., amprenavir, indinavir, or ritonavir), rifampin, alpha-blockers (e.g., doxazosin), or other phosphodiesterase-5 inhibitors
• Current use of alcohol, grapefruit juice, or St. John's wort
• Pregnant or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
6-minute walk distance (measured at Week 3)

Secondary Outcome Measures

Outcome Measure
Oxygen saturation (SpO2) at rest
Lowest SpO2 with exertion (measured during 6-minute walk test)
Total duration of SpO2 below 89% with exertion (measured during 6-minute walk test)
Recovery time (measured during 6-minute walk test)
Mean SpO2 and area under the curve (measured during 6-minute walk test)
Desaturation index (measured by the 6-minute walk distance multiplied by the SpO2 mean value)
Level of breathlessness (measured by Borg dyspnea index questionnaire) (all measured at Week 3)

Collaborators and Investigators

• Sponsor: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: David A. Zisman, MD, University of California, Los Angeles

Publications and helpful links

General Publications

• Collard HR, Anstrom KJ, Schwarz MI, Zisman DA. Sildenafil improves walk distance in idiopathic pulmonary fibrosis. Chest. 2007 Mar;131(3):897-899. doi: 10.1378/chest.06-2101.

Helpful Links

• Click here for the Coalition for Pulmonary Fibrosis web site
• Click here for the UCLA Interstitial Lung Disease Program web site

Study record dates

Study Major Dates

• Study Start: November 1, 2004
• Study Completion (Actual): July 1, 2007

Study Registration Dates

• First Submitted: July 13, 2006
• First Submitted That Met QC Criteria: July 13, 2006
• First Posted (Estimate): July 14, 2006

Study Record Updates

• Last Update Posted (Estimate): July 29, 2016
• Last Update Submitted That Met QC Criteria: July 28, 2016
• Last Verified: December 1, 2007

More Information

Terms related to this study

• Keywords: Pulmonary Hypertension; Idiopathic Pulmonary Fibrosis
• Additional Relevant MeSH Terms: Pathologic Processes; Cardiovascular Diseases; Vascular Diseases; Respiratory Tract Diseases; Lung Diseases; Fibrosis; Hypertension; Pulmonary Fibrosis; Idiopathic Pulmonary Fibrosis; Hypertension, Pulmonary; Molecular Mechanisms of Pharmacological Action; Vasodilator Agents; Urological Agents; Enzyme Inhibitors; Phosphodiesterase Inhibitors; Phosphodiesterase 5 Inhibitors; Sildenafil Citrate
• Other Study ID Numbers: 414; P50HL067665-05 (U.S. NIH Grant/Contract)