ATP and Capsaicin Cough Provocation Test in Chronic Cough and Bronchiectasis

Brief Title

ATP and Capsaicin Cough Provocation Test in Chronic Cough and Bronchiectasis

Official Title

Adenosine Triphosphate and Capsaicin Cough Provocation Test for Identifing Patients With Chronic Cough Who Have Differential Responses to Purinergic Receptor Antagonists: a Randomized, Cross-over, Single-blind Trial

Brief Summary

      This is a randomized, cross-over, single-blind trial. Eligible patients will be randomly
      assigned to undergo either capsaicin or adenosine triphosphate (ATP) cough provocation test,
      followed by a washout period of 2 to 14 days. Participants will be crossed-over to undergo
      another cough provocation test. Patient would be under observation in the out-patient clinics
      for ~2 hours following the cough provocation tests in case of severe adverse events.
    

Detailed Description

      This is a randomized, cross-over, single-blind trial. After verification of the entry
      criteria, eligible patients will be, based on the randomization codes, randomly assigned to
      undergo either capsaicin or ATP cough provocation test (the participants will inhale
      capasaicin or ATP incremental concentration to induce cough, meanwhile the number of coughs
      and adverse events will be recorded in each concentration during the first 30 seconds),
      followed by a washout period of 2 to 14 days (no major changes in the use of concomitant
      medications are allowed,especially the medcines which are not allowed before test ).
      Participants will be crossed-over to undergo another cough provocation test. Patient would be
      under observation in the out-patient clinics for ~2 hours following the cough provocation
      tests in case of severe adverse events. Twenty four hours after each test, a follow-up
      telephone visit will be scheduled for all patients to record any response which may be
      related to the test.
    

Study Type

Observational

Primary Outcome

C5 (Provocant concentration eliciting at least 5 coughs)

Secondary Outcome

 ED50 (half maximal effective Dose)

Condition

Chronic Cough

Intervention

Adenosine Triphosphate

Study Arms / Comparison Groups

 Chronic cough

Description:  patients with chronic cough who remain clinically stable

Publications

* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Status

Diagnostic Test

Estimated Enrollment

200

Start Date

October 29, 2018

Completion Date

July 2020

Primary Completion Date

July 2020

Eligibility Criteria

        Inclusion Criteria:

          -  Out-patients of either gender, ex- or never-smokers, aged between 18 and 60 years

          -  Cough symptoms lasting for more than 8 weeks

          -  Remaining free of acute upper respiratory tract infection for at least 4 weeks

          -  Agreed to participate in the trial and signed informed consent.

        Exclusion Criteria:

          -  Patients with serious systemic diseases (such as malignant tumors), bullae, severe
             uncontrolled asthma, and a history of major hemoptysis

          -  Systemic antibiotic use (except for maintenance low-dose macrolides) within 4 weeks

          -  Pregnancy or lactation

          -  Any known history of sensitivity to ATP or capsaicin

          -  Poor understanding of the test procedure

          -  Diagnosed with cough variant asthma or Eosinophilic bronchitis
      

Gender

All

Ages

18 Years - 60 Years

Accepts Healthy Volunteers

Accepts Healthy Volunteers

Contacts

Ke-fang Lai, MD, +86-13826042052, [email protected]

Location Countries

China

Location Countries

China

NCT ID

NCT03638063

Organization ID

GuangzhouIRD01

Responsible Party

Principal Investigator

Study Sponsor

Guangzhou Institute of Respiratory Disease

Study Sponsor

Ke-fang Lai, MD, Study Chair, Guangzhou Institute of Respiratory Health Locations: China, Guangdong First Affiliated Hospital of Guangzhou Medical

Verification Date

February 2020