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

• Status: Completed
• Trial end date: 2020-01-31
• Target enrollment: 0
• Participant gender: All

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.

• Phase: N/A
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: McMaster University
• Collaborators: AllerGen NCE Inc.; Pharmaxis
• Treatments: Albuterol; Mannitol

Criteria

Inclusion Criteria:

1. Able to understand and give written informed consent

2. Male and female volunteers 18 through 65 years of age.

3. Positive skin-prick test to common aeroallergens (mild allergic asthmatic subjects)

4. Asthma as determined by methacholine provocative concentration causing a 20% fall (PC20) ≤16 mg/ml for mild allergic asthmatic subjects; no airway hyperresponsiveness as determined by methacholine PC20>16mg/ml for normal healthy controls.

5. Baseline FEV1 ≥ 70% of the predicted value for mild allergic asthmatic subjects; baseline FEV1≥ 80% of the predicted value for normal healthy controls.

6. Demonstrate cough response to inhaled mannitol

Exclusion Criteria:

1. Current or former smoker with >10-pack-year history

2. Current or previous history of other significant respiratory disease

3. Significant systemic disease, including history of current malignancy or autoimmune disease

4. Asthma exacerbation or upper/lower respiratory tract infection within the previous 8 weeks

5. Pregnancy

6. Use of corticosteroids within 28 days prior to the first study visit.

7. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) within 48 hours of study visits or aspirin with 7 days of study visits

8. Use of antihistamines including those in cold and allergy medications within 72 hours of study visits

9. Chronic use of other medication for treatment of allergic lung disease other than short-acting β2-agonists.

10. Use of caffeine-containing products within 4 hours of study visits

11. Use of Angiotensin converting enzyme inhibitors (ACE inhibitors)

12. Any centrally acting medication which in the view of the investigator could alter the sensitivity of the cough reflex including but not restricted to tricyclic anti-depressants, pregabalin, gabapentin, codeine, tramadol, or any other opioid.

13. Lung disease other than mild to moderate allergic asthma, for mild allergic asthmatic subjects; no lung disease for normal healthy controls.

14. Unwillingness or inability to comply with the study protocol for any other reason.