A Phase 2 interventional study of L-menthol and Placebo in Asthma, sponsored by Region Skane. Recruiting at 2 sites in Sweden. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-19.
Sponsored by Region Skane · Phase 2, Interventional, and Basic science
The purpose of this study is to assess the effect of L-menthol on breathlessness and exercise capacity in patients with Asthma.
Dyspnea is a cardinal symptom in patients with lung disease, often triggered by daily-life physical activities. 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 and ILD 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 patients with Asthma.
Exclusion Criteria:
In the trial, prior to performing submaximal cardio-pulmonary exercise testing (CPET), participants will be administered, L-menthol patch which will be attached to the inside of a facemask that is connected to the breathing circuit.
Drug: L-menthol
For placebo, the patch will contain a similarly patch with strawberry scent.
Other: Placebo
(Sigma-Aldrich, St. Louis, US)
Strawberry scent (Sigma-Aldrich, St. Louis, US)
Breathlessness intensity
The difference between treatment conditions in dyspnea intensity at iso-time. The Borg's modified 0-10 category ratio scale (Borg CR10) will be used, where 0 represents no perceived breathlessness at all, and 10 represents maximum breathlessness intensity ever experienced.
Time frame: During submaximal test, at isotime during day 2 and day 3.
Dyspnea unpleasantness
The difference between treatment conditions in dyspnea unpleasantness at iso-time. The Borg's modified 0-10 category ratio scale (Borg CR10) will be used, where 0 represents no perceived unpleasantness at all, and 10 represents maximum breathlessness unpleasantness experienced.
Time frame: During submaximal test, at iso-time during day 2 and day 3
Total time
Time to the limit of tolerance (s) (tLIM)
Time frame: At the end of submaximal test during day 2 and day 3.
Exercise capacity
V'O2 (aerobic exercise capacity, absolute and in %pred)
Time frame: Submaximal test during day 2 and day 3.
Peak dyspnea intensity
Dyspnea intensity at peak exercise. The Borg's modified 0-10 category ratio scale (Borg CR10) will be used, where 0 represents no perceived breathlessness at all, and 10 represents maximum breathlessness intensity ever experienced.
Time frame: During submaximal test, at peak during day 2 and day 3.
Leg fatigue
The Borg's modified 0-10 category ratio scale (Borg CR10) will be used, where 0 represents no perceived leg fatigue at all, and 10 represents maximum leg fatigue ever experienced.
Time frame: During submaximal test, at day 2 and day 3.
Ventilatory efficacy
Efficacy of ventilation (VE/V'CO2-slope)
Time frame: During submaximal test, at day 2 and day 3.
Saturation
O2-Saturation
Time frame: During submaximal test, at day 2 and day 3.
Stop reason
Causes of stopping the test
Time frame: During submaximal test, at day 2 and day 3.
Adverse events
Any adverse events during the test
Time frame: Through study completion, an average of 1 week.
Respiratory exchange ratio
Respiratory exchange ratio (RER), defined as V'CO2/V'O2
Time frame: During the submaximal test at day 2 and day 3.
Heart rate
Heart rate in beats/min
Time frame: During the submaximal test at day 2 and day 3.
Breathing frequency
Breathing frequency in breaths/min
Time frame: During the submaximal test at day 2 and day 3.
Minute ventilation
Ventilation per minute
Time frame: During the submaximal test at day 2 and day 3.
Tidal volume
Tidal volume in liters
Time frame: During the submaximal test at day 2 and day 3.
Ventilatory reserve
Defined as maximal voluntary ventilation (MVV) - VE
Time frame: During the submaximal test at day 2 and day 3.
Plan to share: No
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Region Skane