Efficacy of L-menthol on Breathlessness in Chronic Obstructive Pulmonary Disease

Breathelssness (Dyspnea) is a cardinal symptom in patients with chronic obstructive pulmonary disease (COPD), often triggered by daily-life physical activities. Despite optimal treatment of the underlying disease, many patients still suffer from chronic and disabling dyspnea for many years, leading to exercise intolerance, and worse morbidity and mortality. To date, an effective pharmacologic treatment to relieve chronic dyspnea is lacking. Recent pilot data support that inhaled L-menthol can markedly decrease laboratory-induced dyspnea in COPD patients, likely through increased afferent feedback of airflow in the airways by inducing a cooling sensation through olfactory stimulation. The aim of this study is therefore to assess the effectiveness and mechanisms of inhaled menthol for relief of chronic dyspnea in patients with COPD.

Inclusion criteria

• The subject has given written consent to participate in the study
• Diagnosis of COPD confirmed by spirometry and a FEV1 < 80% of predicted post bronchodilator at baseline
• age 18 years or older
• able to cycle
• able to understand and talk Swedish to participate in the study procedures, as judged by the Investigator.

Exclusion criteria

• Resting peripheral oxygen saturation (SpO2) < 92%
• hospitalization or clinical instability during the last four weeks
• treatment with supplementary oxygen at rest or during exercise
• contraindication to exercise testing in accordance with clinical practice guidelines
• expected survival shorter than six months as judged by the Investigator
• medical conditions including congestive heart failure, acute coronary artery disease, neuromuscular diseases, severe psychiatric illness, and olfaction disorder.