The Role of Substance P on Perception of Breathlessness During Resistive Load Breathing

Substance P is released from sensory nerves and transmits pain information into the central nervous system. As pain and dyspnea share many characteristics, including similar neurological pathways, it is possible that substance P may contribute to the sensation of dyspnea. The hypothesis of the study is that patients with chronic obstructive pulmonary disease (COPD) will provide lower ratings of breathlessness during resistive load breathing with oral aprepitant, a medication that blocks the activity of substance P, compared with placebo.