Investigating the interaction between airway narrowing and cough in asthma
- Conditions
- Mild atopic asthmaRespiratoryAsthma
- Registration Number
- ISRCTN14900082
- Lead Sponsor
- niversity Hospital of South Manchester
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Completed
- Sex
- All
- Target Recruitment
- 15
1. Aged =18
2. Have taken part in Studying Cough in Asthma Phenotypes” (CoAst) study
3. Person with a diagnosis of atopic asthma (based on a positive skin prick test)
4. The subject is treated with:
4.1. Short acting Beta 2 Agonist PRN AND/OR
4.2. Inhaled corticosteroid (=250 mcg fluticasone propionate daily or equivalent)
5. Controlled or has partial asthma control according to GINA classification
1. Subjects who have previously coughed less than a total of four coughs in one dose at the ED50 dose of capsaicin inhalation (assess after visit 1)
2. Subjects who bronchoconstrict by more than 10% at the end of the full dose capsaicin cough challenge (assess after visit 1)
3. Subjects who do not display evidence of airway hyper-responsiveness (PC20 >8 mg/ml) (assess after visit 2)
4. Symptoms of upper respiratory tract infection (URTI) in the last 1 month which have not resolved
5. Lower respiratory tract infection or pneumonia in the last 6 weeks
6. Current smoker or ex-smoker with =10 pack-year smoking history and abstinence of =6 months
7. Asthma exacerbation in the previous month requiring an increase or start of an ICS or OCS
8. Asthma medication which include theophylline or anti-cholinergic drugs
9. Subject has changed asthma medication within the past 4 weeks prior to screening
10. A previous asthma exacerbation requiring Intensive Care Unit (ICU) admission
11. Significant other primary pulmonary disorders, in particular: pulmonary embolism, pulmonary hypertension, interstitial lung disease, lung cancer, cystic fibrosis, emphysema or bronchiectasis
12. Pregnancy or breastfeeding
13. Use of ACE inhibitors
14. Any centrally acting medication which in the view of the investigator could alter the sensitivity of the cough reflex*
15. History of psychiatric illness, drug or alcohol abuse which may interfere in the participation of the trial
*Any participant who is taking tricyclic anti-depressants, pregabalin, gabapentin or opioids will not be eligible to take part in this study unless they are willing and medically able to withdraw from such medication for the duration of the study. The reason for this is that centrally acting medications may alter the sensitivity of the cough reflex
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method 1. The number of coughs evoked by an ED50 dose of capsaicin after methacholine-induced bronchoconstriction compared with saline inhalation<br>2. The % drop in FEV1 after inhaling methacholine immediately after coughing evoked by an ED50 dose of capsaicin compared to saline (0.9%)
- Secondary Outcome Measures
Name Time Method The secondary outcome will be to explore the number of coughs throughout the duration of each visit, and in particular during methacholine challenges and the recovery periods after salbutamol is given