Sildenafil Effects on Pulmonary Haemodynamics and Gas Exchange in Chronic Obstructive Pulmonary Disease (COPD)
Status:
Completed
Trial end date:
2009-02-01
Target enrollment:
Participant gender:
Summary
Sildenafil is a phosphodiesterase-5 inhibitor that has been approved for the treatment of
pulmonary arterial hypertension with orphan drug designation. Sildenafil modulates the nitric
oxide (NO) pathway in the vessel wall. Since this pathway is impaired in pulmonary arteries
of patients with pulmonary hypertension (PH) associated with chronic obstructive pulmonary
disease (COPD), we hypothesized that sildenafil might improve pulmonary hemodynamics and
increase exercise tolerance in this condition. However, in COPD sildenafil may also impair
gas exchange due to the inhibition of pulmonary hypoxic vasoconstriction. The research
project is aimed to evaluate these effects.
It is a prospective, randomized, double-blind study to evaluate the acute effects of a single
dose of 20 or 40 mg of sildenafil on gas exchange and pulmonary hemodynamics. Subjects: 20
patients (10 in each group). Measurements: pulmonary hemodynamics, arterial blood gasses and
ventilation-perfusion distributions; at rest and during sub-maximal exercise.