Chronic cough Signs and Symptoms Cough
Conditions
Interventions
Phase 1 (healthy volunteers):
A pilot study to identify in healthy individuals the threshold concentration of inhaled citric acid that induces somatic sensations such as irritation, and then the subse
Sponsors
University Hospital of South Manchester NHS Foundation Trust
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Phase 1 (healthy volunteers): 1. Healthy male or female aged over 18 years 2. Nonsmoker 3. Normal spirometry 4. No history of asthma Phase 2 (chronic cough patients): 1. Male or female age over 18 years 2. Diagnosed with idiopathic chronic cough (greater than 8 weeks duration) 3. Normal spirometry 4. Treated with low dose (5 to 10 mg) Morphine Sulphate twice daily and willing to temporarily withdraw morphine treatment for study purposes
Exclusion criteria
Exclusion criteria: Phase 1 (healthy volunteers): 1. Male or female 2 years postmenopausal and/or not surgically sterilised) must have a negative urine pregnancy test, performed at visit 1 prior to administration of study medication 5. Current smokers or exsmokers with 10 pack years 6. Current treatment with ACE inhibitors 7. Drug or alcohol abuse 8. Uncontrolled hypertension (i.e., >160/90 mmHg despite adequate medical therapy) 9. Recent myocardial infarction, or history of congestive cardiac failure 10. Any clinically significant neurological disorder 11. Any clinically significant or unstable medical or psychiatric condition that would interfere with the patient’s ability to participate in the study
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Phase 1 (healthy volunteers): To evaluate the differences in citric acid threshold at which initial throat sensations and the urge to cough are reported Phase 2 (chronic cough patients): To evaluate the within-subject differences in urge-to-cough (UTC) ratings with citric acid inhalation with morphine compared with placebo therapy | — |
Secondary
| Measure | Time frame |
|---|---|
| Phase 1 (healthy volunteers): 1. To investigate the relationship between citric acid dose for first detectable throat sensation and somatosensory amplification scale 2. To investigate the relationship between citric acid dose for first detectable throat sensation and state/trait anxiety Phase 2 (chronic cough patients): 1. To evaluate the differences in citric acid threshold at which initial throat sensations and the urge to cough are reported 2. To compare with healthy controls the differences in citric acid threshold at which initial throat sensations and the urge to cough are reported 3. To evaluate the within subject differences in respiratory rate with morphine compared with placebo therapy 4. To evaluate the within subject differences in objective cough frequency with morphine compared with placebo therapy 5. To evaluate the within subject differences in intensity and unpleasantness rating of UTC with morphine compared with placebo therapy 6. To explore the relationships between state anxiety, somatosensory amplification and citric acid thresholds and the response to morphine | — |
Countries
United Kingdom
Outcome results
None listed