Sildenafil for Chronic Obstructive Pulmonary Disease

Phase 2

Completed

Conditions: Pulmonary Disease, Chronic Obstructive
Emphysema

Interventions: Drug: sildenafil citrate
Drug: Placebo

Registration Number: NCT00104637

Lead Sponsor: Kawut, Steven, MD

Brief Summary: The purpose of this study is to determine if sildenafil improves the exercise capacity and lung function of patients with chronic obstructive pulmonary disease.

Detailed Description: Patients with chronic obstructive pulmonary disease (COPD) suffer from impaired exercise capacity and quality-of-life, largely related to shortness of breath. Many of the therapies currently available for COPD are aimed at improving these factors. Exercise capacity is limited in part by high blood pressure in the blood vessels in the lungs. Sildenafil, also known as Viagra, is an FDA-approved therapy for male erectile dysfunction. One of its effects is to relax (or open) the lung vessels, thereby lowering the blood pressure in the lungs. We hypothesize that sildenafil will result in an improvement in exercise capacity, quality-of-life, and shortness of breath.

Enrolled subjects will receive sildenafil or placebo for 4 weeks followed by exercise tests, breathing tests, and administration of quality-of-life questionnaires. Subjects will then receive placebo or sildenafil (whichever one they did not receive for the first 4 weeks) for another 4 weeks, followed by the same testing.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 10

Inclusion Criteria

Clinical diagnosis of chronic obstructive pulmonary disease (COPD) or emphysema
FEV1/FVC ratio < 70%
FEV1 < 80%
Stable medication regimen

Exclusion Criteria

COPD exacerbation or hospitalization in the past 3 months
Heart disease
Contraindication to sildenafil
Unrelated lung disease
Inability to walk or pedal on a stationary bike
Pregnancy or breast-feeding
Pulmonary hypertension at rest

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Sildenafil / Placebo	sildenafil citrate	Sildenafil first, followed by washout, followed by placebo
Sildenafil / Placebo	Placebo	Sildenafil first, followed by washout, followed by placebo
Placebo / Sildenafil	sildenafil citrate	Placebo first, followed by washout, followed by Sildenafil
Placebo / Sildenafil	Placebo	Placebo first, followed by washout, followed by Sildenafil

Primary Outcome Measures

Name	Time	Method
6 Minute Walk Distance	Period 1 and Period 3 ( within 8 weeks)	The distance a subject walked within 6 minutes was measured and documented.
VO2 Peak (Oxygen Consumption at Peak Exercise)	Period 1 and Period 3 ( within 8 weeks)	Oxygen consumption at peak exercise was measured at scheduled timepoints during treatment periods 1 and 3.

Secondary Outcome Measures

Name	Time	Method
Pulmonary Function FVC (Forced Vital Capacity)	Period 1 (4 weeks)	Data to calculate results for FVC was based on Period 1.
Forced Expiratory Volume in the First Second (FEV1 )	Period 1 ( 4 weeks)	The volume of air exhaled in the first second. Data to calculate results for FEV1 was based on Period 1 only.
Borg Dyspnea(Scale That Measures Breathlessness) Score at Finish of 6 Minute Walk Test (6MWT)	Period 1 and Period 3 ( within 8 weeks)	Participants were asked to scale the breathlessness felt at the end of 6MWT from 0 to 10, with 0 being the least discomfort and 10 being the most discomfort in breathing.
Diffusing Capacity of Carbon Monoxide (DLCO)	Period 1 and Period 3 ( within 8 weeks)	Carbon Monoxide Diffusing Capacity was measured on the same days as the pulmonary function tests.
Partial Pressure of Carbon Dioxide (PCO2) in Arterial Blood Gas (ABG)	Period 1 and Period 3 ( within 8 weeks)	Partial pressure of carbon dioxide in ABG performed breathing room air at rest.
Partial Pressure of Oxygen (PO2) in Arterial Blood Gas (ABG)	Period 1 and Period 3 ( within 8 weeks)	Partial Pressure of Oxygen in ABG breathing room air at rest.
A-a Gradient (Alveolar-arterial Gradient)	Period 1 and Period 3 ( within 8 weeks)	A-a gradient was measured with ABG breathing room air at rest.
Oxygen Pulse	Period 1 and Period 3 ( within 8 weeks)	Oxygen pulse during Cardiopulmonary exercise test at peak exercise.
O2 Saturation at Peak Exercise	Period 1 and Period 3 ( within 8 weeks)	O2 Saturation at Peak Exercise measured during the Cardiopulmonary exercise test.