An Investigation Into the Mechanism of Inhalation Cough Challenge

Launched by HULL UNIVERSITY TEACHING HOSPITALS NHS TRUST · Jan 16, 2014

Keywords

ClinConnect Summary

The investigators have previously demonstrated that mild acids, such as citric, tartaric or phosphoric acid produce a highly reliable cough challenge and that the sensitivity of these are complex individual acids correlates within the population studied inferring a common mechanism of action.In contrast there is no correlation with the other common cough challenge methodology, capsaicin inferring that there are at least two different mechanisms for producing cough with aerosols in man.

Over the past 10 years it has been established that capsaicin works by a specific irritant receptor known...

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Patients will be required to demonstrate significant cough symptoms by a score greater than 20/70 on the Hull Airways Reflux Questionnaire.
• • All patients must be current non-smokers.
• • Patients must be on stable medication for at least one month.
• • Patients must be able to attend the trials unit on at least 3 occasions.
• • Patients must have normal lung function patients must be able to give informed consent
• Exclusion Criteria:
• • Subjects who are pregnant, or have pacemakers in situ are excluded from this study.
• • Those with a serious comorbid conditions such as cancer, severe COPD, or heart failure will be excluded.
• • Those who are non-English speakers and special groups (i.e. mentally ill, children under 16 years of age, and those suffering from dementia) will be excluded.
• • No test will be performed on any subject during an acute worsening of asthma or upper airway infection. If the subject has had an upper airway infection in the last three weeks they will be offered another appointment.
• • If the subject has taken any over the counter (OTC) cough mixture within the last twelve hours: If the subject is willing to come back another time for challenge testing, another appointment should be made.
• • If the subject has had any food or drink products containing caffeine or menthol within the last hour. If the subject is unwilling to wait for 1 hour before starting the test, the subject should return another time. If the subject is unwilling to return another time, testing should proceed and the medication used recorded.
• • If the participant is currently involved in research, or within 3 months of participation in any type of research, they will be excluded from this study.