Chronic cough Respiratory Chronic cough
Conditions
Interventions
Basal conditions:
During both blocks of capsaicin inhalation (block 1 and block 2) participants will not place their hand in a water bath and will be instructed to cough freely.
Control conditions:
Sponsors
University Hospitals of South Manchester NHS Foundation Trust (UK)
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Healthy volunteers: 1. Aged over 18 years old, either sex 2. Normal lung function 3. No current or past history of chronic cough or chronic respiratory illness 4. No current or past history of chronic pain, irritable bowel syndrome or chronic headaches 5. No current or past history of psychiatric illness 6. No current history of reflux disease or post-nasal drip syndrome Chronic cough patients: 1. Aged over 18 years old, either sex 2. Chronic cough, defined as a cough lasting longer than 8 weeks despite investigation and/or treatment trials for cough variant asthma, post-nasal drip and gastro-oesophageal reflux disease 3. Normal chest x-ray 4. Normal lung function 5. Can safely omit long-acting bronchodilators (if taking)
Exclusion criteria
Exclusion criteria: 1. Recent upper respiratory tract infection (less than 4 weeks) 2. Pregnancy or breastfeeding 3. Use of angiotensin converting enzyme (ACE) inhibitors 4. Any centrally acting medication which could alter the sensitivity of the cough reflex 5. History of drug or alcohol abuse 6. Current smoker or ex-smoker with greater than 10 pack year smoking history
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Effect of painful cold water bath on cough response, recorded following each of the four randomised interventions. Each intervention will take place at least 48 hours apart. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Effect of conscious cough suppression on cough response 2. Comparison of effects by group and gender The primary and secondary outcome measures will be recorded following each of the four randomised interventions. Each intervention will take place at least 48 hours apart. | — |
Countries
United Kingdom
Outcome results
None listed