NCT01297790

Cough Responses to Tussive Agents in Health and Disease

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 102 (actual)
• Sponsor: Manchester University NHS Foundation Trust · Other Government
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

The sensitivity of a persons cough reflex can be measured by getting them to breath in (inhale) irritant chemicals. The purpose of this clinical research study is to test the sensitivity of the cough reflex to a variety of chemicals that can be inhaled to see if coughing responses are different between healthy people and people with respiratory problems that make them cough.

Detailed description

Coughing is a distressing symptom which has a major impact on quality of life. It has been estimated that cough costs the UK economy £1 billion each year. Currently there are no effective anti-tussive agents to treat subjects with cough. Although drugs such as morphine may have some anti-tussive effect, side effects unacceptable. Currently our understanding of the mechanisms which lead to coughing in different diseases is poor. Many mechanistic studies rely on testing the sensitivity of the cough reflex by inhalation of capsaicin (chilli-pepper extract) or citric acid. These challenges do not differentiate well between health and disease or between different disease states. Other agents such as prostaglandins and bradykinin are known to stimulate a coughing but responses to these agents have rarely been used as a measure of cough reflex sensitivity and not been compared to standard challenges. It is clear that patients with common airway diseases such as COPD and asthma cough significantly more than healthy subjects. Moreover subjects presenting with chronic cough have cough rates an order of magnitude higher than most patients with airway disease. These differences are poorly represented by the differences in current cough challenge tests. The investigators hypothesize that patterns of cough responses to different tussive agent may better differentiate between health and different disease states. These patterns may also suggest the different mechanisms leading to cough in different diseases.

Conditions

• Chronic Obstructive Airway Disease
• Asthma
• Chronic Cough

Interventions

Type	Name	Description
OTHER	Cough Challenge Tests	Inhalational cough challenge tests with capsaicin, bradykinin, Citric acid and prostaglandin E2
OTHER	ambulatory cough recording	Cough recording with a portable device to capture cough sounds
OTHER	Cough questionnaires	Questionnaires designed to study cough. These include Leicester cough questionnaire, cough visual analogue score and cough quality of life questionnaire.

Timeline

• Start date: 2009-11-01
• Primary completion: 2011-05-01
• Completion: 2011-05-01
• First posted: 2011-02-17
• Last updated: 2011-09-16

Locations

1 site across 1 country: United Kingdom