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Reference Ranges for the Cough Responsiveness to Inhaled Mannitol

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT05034367
Recruitment Status : Recruiting
First Posted : September 5, 2021
Last Update Posted : September 5, 2021
John Hunter Hospital
Royal Prince Alfred Hospital, Sydney, Australia
Information provided by (Responsible Party):
Heikki Koskela, Kuopio University Hospital

Brief Summary:

Cough is the most common reason why people seek medical attention in developed countries. The main mechanisms for prolonged cough are hypersensitivity of the cough reflex arc, sputum production, and constriction of the airway smooth muscles. Recognition of the mechanism in each cough patient is essential for the efficient management of prolonged cough. At present, there are no feasible tests for everyday clinical work to recognize cough reflex arc hypersensitivity.

Mannitol test was originally developed for asthma diagnostics. We have recently shown that it can also be used to investigate hypersensitive cough reflex arc. The purpose of the present study is to create reference ranges for normal cough responsiveness to inhaled mannitol. Without them, the test cannot be utilized in everyday clinical work. For that purpose we will perform mannitol test in 140 subjects, who are at least 18 years old and without any chronic respiratory symptoms or disorders. The subjects will be recruited in three centers: University of Eastern Finland and two Australian hospitals: John Hunter Hospital and Royal Prince Alfred Hospital.The material will be collected 1.9.2021-31.12.2022. We apply funding for both personnel and material expences, to carry out this study.

Condition or disease Intervention/treatment Phase
Cough Diagnostic Test: Mannitol challenge Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 140 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Reference Ranges for the Cough Responsiveness to Inhaled Mannitol
Estimated Study Start Date : September 2021
Estimated Primary Completion Date : December 2022
Estimated Study Completion Date : December 2022

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Cough
Drug Information available for: Mannitol

Arm Intervention/treatment
Experimental: Healthy persons
The responses of the healthy subjects are utilized to create reference ranges for a normal cough response to mannitol
Diagnostic Test: Mannitol challenge
Inhalation challenge with dry powder of mannitol with a maximal cumulative dose of 635 mg

Primary Outcome Measures :
  1. Cough-to-dose ratio [ Time Frame: Coughs are recorded during the 60 seconds after each mannitol dose ]
    calculated as the number of coughs per 100 mg of total cumulative dose of mannitol

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • age 18 years or older
  • capable to understand the purpose of the study
  • female/male ratio approximately 50%/50% in both of the following age groups:
  • 50% aged 18- 50 yrs, and 50 % aged 51 - 90 years

Exclusion Criteria:

  • Current daily smoking
  • Ex-smoking with a greater than 10 pack years' daily smoking history or with stopping of daily smoking less than one year ago
  • Pregnancy and breastfeeding
  • A doctor's diagnosis of any respiratory diseases, including both upper and lower airway diseases, lung parenchymal diseases and the sleep apnoea syndrome
  • A doctor's diagnosis of gastro-oesophageal reflux disease or symptoms suggestive of it
  • Current use of angiotensin-converting enzyme inhibitors
  • Upper respiratory tract infection ('flu') within 4 weeks
  • Any current (within 4 weeks) cough 8
  • Chronic (over 2 months' duration) cough during the last 12 months
  • Wheezing during the last 12 months
  • Attacks of shortness of breath or cough at night during the last 12 months
  • Symptoms of rhinitis in a prolonged fashion during the last 12 months
  • Heartburn or regurgitation once a week or more often during the last 3 months
  • Abnormal anatomy of the respiratory organs, which may affect the deposition of the mannitol powder
  • Any previous operations to the respiratory organs that can affect the deposition of the mannitol powder
  • Unable to provide written informed consent to participate in the study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT05034367

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Contact: Heikki O Koskela, MD +358 447172795
Contact: Hanna M Nurmi, MD +358 447179973

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Australia, New South Wales
John Hunter Hospital Recruiting
Newcastle, New South Wales, Australia, 2305
Contact: John D Brannan, PhD    +61 435 206 232   
Royal Prince Alfred Hospital Recruiting
Sydney, New South Wales, Australia, 2050
Contact: Keith Wong, PhD    +61 2 9515 6652   
Kuopio University Hospital Recruiting
Kuopio, Finland, 70029
Contact: Heikki O Koskela, MD    +358 447172795   
Sponsors and Collaborators
Kuopio University Hospital
John Hunter Hospital
Royal Prince Alfred Hospital, Sydney, Australia
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Responsible Party: Heikki Koskela, Chief physician, Kuopio University Hospital Identifier: NCT05034367    
Other Study ID Numbers: 5801151
First Posted: September 5, 2021    Key Record Dates
Last Update Posted: September 5, 2021
Last Verified: September 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Additional relevant MeSH terms:
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Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Diuretics, Osmotic
Natriuretic Agents
Physiological Effects of Drugs