Neurophysiology and Pharmacology of Cough Reflex Hypersensitivity

June 17, 2013 updated by: Jacky Smith

A cough lasting more than 2 months is known as a chronic cough, affecting 12-23% of the adult non-smoking population. Chronic cough has many associated complications including incontinence, muscular chest pains, blackouts and depression. Current treatment is often ineffective in these patients. To develop new medications the investigators need to understand more about the mechanisms that can lead to excessive coughing.

This study plans to compare a group of 12 healthy volunteers and 12 patients with a chronic cough. The investigators hypothesise that that chronic cough patients have a more sensitive cough reflex as a result central nervous system hyper-excitability (central sensitisation). The investigators will measure cough reflex sensitivity before and after administration of ketamine, a medication that blocks an important receptor in the central nervous system.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

24

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
      • Manchester, United Kingdom, M23 9LT
        • University of Manchester, Education and Research Centre, Wythenshawe Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years to 76 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Healthy Volunteers:

  • Over 18 years old
  • Measurable cough reflex sensitivity
  • No current or past history of chronic cough or chronic respiratory disease.
  • No symptoms of gastro-oesophageal reflux disease, asthma or post-nasal drip.

Chronic Cough Patients

  • Over 18 years old
  • Chronic persistent cough (> 8 weeks) despite investigation and/or treatment trials for cough variant asthma/post nasal drip and gastro-oesophageal reflux disease.
  • Normal CXR
  • Normal lung function
  • Measurable cough reflex sensitivity

Exclusion Criteria:

  • Recent Upper Respiratory Tract Infection (4 weeks)
  • Pregnancy/breast feeding
  • Current smokers or ex-smokers with < 6 months abstinence or cumulative history of > 10 packyears
  • Diabetes Mellitus
  • Opiate or ACE Inhibitor use.
  • Any centrally acting medication which has the potential to alter cough reflex sensitivity.
  • Significant and ongoing chronic respiratory, cardiovascular (in particular hypertension), gastro-intestinal, haematological (porphyria), neurological or psychiatric illness.
  • Drug or alcohol abuse
  • History of allergy or reaction to ketamine of other NMDA receptor antagonists.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Health Services Research
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Healthy Volunteers
Drug: ketamine
Administration of low dose intravenous ketamine. Dose: 0.075mg/kg over 10 minutes followed by 0.005mg/kg/min over 20 minutes. Given as single infusion.
Active Comparator: Chronic Cough Patients
Drug: ketamine
Administration of low dose intravenous ketamine. Dose: 0.075mg/kg over 10 minutes followed by 0.005mg/kg/min over 20 minutes. Given as single infusion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Cough Reflex Sensitivity
Time Frame: 6 months
6 months

Secondary Outcome Measures

Outcome Measure
Time Frame
Upper Oesophageal Pain Thresholds
Time Frame: 6 months
6 months
Pain Thresholds Pharynx
Time Frame: 6 months
6 months
Pain Thresholds Chest Wall
Time Frame: 6 months
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Jacky Smith

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2008

Primary Completion (Actual)

July 1, 2009

Study Completion (Actual)

July 1, 2009

Study Registration Dates

First Submitted

March 9, 2009

First Submitted That Met QC Criteria

March 9, 2009

First Posted (Estimate)

March 10, 2009

Study Record Updates

Last Update Posted (Estimate)

June 19, 2013

Last Update Submitted That Met QC Criteria

June 17, 2013

Last Verified

June 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 07/H1004/142

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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