Efficacy of L-menthol on Breathlessness in Asthma (Ment-Astma)

Effect of L-menthol on Breathlessness and Exercise Capacity in Asthma: a Randomized Crossover Trial

The purpose of this study is to assess the effect of L-menthol on breathlessness and exercise capacity in patients with Asthma.

Study Overview

• Status: Not yet recruiting
• Conditions: Asthma
• Intervention / Treatment: Drug: L-menthol; Other: Placebo

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Zainab Ahmadi, MD, PhD; Phone Number: 046171000; Email: zainab.ahmadi@med.lu.se

Study Locations

• Sweden
  • Lund, Sweden
    • Lund University hospital and Region Skåne
    • Contact: Zainab Ahmadi, MD, PhD; Phone Number: 046171000; Email: zainab.ahmadi@med.lu.se
  • Blekinge County
    • Karlskrona, Blekinge County, Sweden
      • Blekinge Institute of Technology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• the subject has given written consent to participate in the study
• physician diagnosis of Asthma according to international guidelines
• mMRC (modified Medical Research Council) score of 1 or above
• age 18 years or older
• able to cycle
• able to understand and talk Swedish to participate in the study procedures, as judged by the Investigators.

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; For placebo, the patch will contain a similarly patch with strawberry scent.	Other: Placebo; Strawberry scent (Sigma-Aldrich, St. Louis, US)
Experimental: L-menthol; 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; (Sigma-Aldrich, St. Louis, US)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	During submaximal test, at isotime during day 2 and day 3.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total time	Time to the limit of tolerance (s) (tLIM)	At the end of submaximal test during day 2 and day 3.
Exercise capacity	V'O2 (aerobic exercise capacity, absolute and in %pred)	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.	During submaximal test, at peak during day 2 and day 3.
Respiratory exchange ratio	Respiratory exchange ratio (RER), defined as V'CO2/V'O2	During the submaximal test at day 2 and day 3.
Heart rate	Heart rate in beats/min	During the submaximal test at day 2 and day 3.
Breathing frequency	Breathing frequency in breaths/min	During the submaximal test at 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.	During submaximal test, at iso-time 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.	During submaximal test, at day 2 and day 3.
Ventilatory efficacy	Efficacy of ventilation (VE/V'CO2-slope)	During submaximal test, at day 2 and day 3.
Saturation	O2-Saturation	During submaximal test, at day 2 and day 3.
Stop reason	Causes of stopping the test	During submaximal test, at day 2 and day 3.
Adverse events	Any adverse events during the test	Through study completion, an average of 1 week.
Minute ventilation	Ventilation per minute	During the submaximal test at day 2 and day 3.
Tidal volume	Tidal volume in liters	During the submaximal test at day 2 and day 3.
Ventilatory reserve	Defined as maximal voluntary ventilation (MVV) - VE	During the submaximal test at day 2 and day 3.

Collaborators and Investigators

• Sponsor: Region Skane
• Collaborators: Blekingesjukhuset, Karlskrona; Blekinge Institute of Technology

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: March 24, 2026
• First Submitted That Met QC Criteria: March 24, 2026
• First Posted (Actual): March 30, 2026

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 24, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: asthma; exercise capacity; CPET; breathlessness
• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Asthma; Dyspnea; Organic Chemicals; Lipids; Hydrocarbons; Cyclohexanes; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Alcohols; Cyclohexanols; Hexanols; Fatty Alcohols; Cyclohexane Monoterpenes; Monoterpenes; Menthol
• Other Study ID Numbers: Ment-Astma

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No