Mannitol-Induced Cough Challenge in Healthy Controls and Subjects With Mild Allergic Asthma — MICC  

Asthma Clinical Trial

Official title: Mannitol-Induced Cough Challenge in Healthy Controls and Subjects With Mild Allergic Asthma

Status Completed

Clinical Trial Summary

The study aim is to investigate if changes in osmolarity using mannitol challenge can evoke coughing reproducibly in mild allergic asthmatics compared with healthy controls and if salbutamol can affect this. Phase 1 of this study is a reproducibility analysis of cough dose response to mannitol in a cohort of mild allergic asthmatics and healthy controls. Phase 2 is a double-blind, placebo-controlled analysis in mild allergic asthmatics assessing the effects of salbutamol on mannitol induced cough.

Clinical Trial Description

The study will have a maximum of 4 visits separated by at least 24 hours. The first 2 visits will determine eligibility. All eligible subjects will be invited back for a third visit, and only subjects with mild allergic asthma will be invited back for a fourth visit.

Screening Period (Visits 1 and 2) - For All Subjects Eligible subjects will be identified during the initial screening procedures with measures of spirometry, hyperresponsiveness to methacholine, complete history, physical examination, allergen skin test, and mannitol cough challenge. The screening procedures will be conducted over 2 separate visits.

Reproducibility (Visit 3) - For Healthy Controls Ten normal healthy controls meeting study eligibility will return for visit 3. This visit must be at least 24h after the mannitol test at visit 1. These data will be used for assessing reproducibility of the mannitol induced coughs; Emax and the median effective dose (ED50).

Effects of Salbutamol (Visit 3 and 4) - For Mild Allergic Asthma Subjects Ten subjects with mild allergic asthma will return for visit 3 and 4. These visits must be at least 24h apart and no longer than 7 days. Mild allergic asthmatics will first receive salbutamol 2.5mg or saline placebo via a nebuliser and 15 mins later the forced expiratory volume at one second (FEV1) measured. Subjects will then undergo a mannitol cough challenge exactly like the previous mannitol cough challenges. These data will be used for determining the effects of salbutamol on mannitol-induced bronchoconstriction and cough.

Visit Windows Each visit must be separated by a minimum of 24 hours, and a maximum of 7 days. Study visits can be performed in the morning or afternoon, however for each subject the timing should be consistent with Visits 2 at the same time of day ± 2 hours ;

Related Conditions & MeSH terms

• Asthma
• Cough

• NCT number: NCT03620422
• Study type: Interventional
• Source: McMaster University
• Status: Completed
• Phase: N/A
• Start date: January 11, 2019
• Completion date: January 31, 2020