Neurophysiology and Pharmacology of Cough Reflex Hypersensitivity

Ketamine

Brief Summary

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.

Intervention / Treatment

  • Ketamine (DRUG)
    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.

Condition or Disease

  • Chronic Cough

Phase

  • Not Applicable

    • Study Design

    Study type: INTERVENTIONAL
    Status: Completed
    Study results: No Results Available
    Age: 18 Years to 80 Years
    Enrollment: 24 (ACTUAL)
    Funded by: Other
    Allocation: Randomized
    Primary Purpose: Health Services Research

    Masking

    DOUBLE:
    • Participant
    • Investigator

    Clinical Trial Dates

    Start date: Feb 01, 2008
    Primary Completion: Jul 01, 2009 ACTUAL
    Completion Date: Jul 01, 2009 ACTUAL
    Study First Posted: Mar 10, 2009 ESTIMATED
    Results First Posted: Aug 31, 2020
    Last Updated: Jun 17, 2013

    Sponsors / Collaborators

    Lead Sponsor: Jacky Smith
    Responsible Party: Jacky Smith

    Location

    Manchester, England, United Kingdom

    Participant Groups

    • No description provided

    • No description provided

    Eligibility Criteria

    Sex: All
    Minimum Age: 18
    Maximum Age: 80
    Age Groups: Adult / Older Adult
    Healthy Volunteers: Yes

    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.

    Primary Outcomes
    • Cough Reflex Sensitivity 6 months
    Secondary Outcomes
    • Upper Oesophageal Pain Thresholds 6 months
    • Pain Thresholds Pharynx 6 months
    • Pain Thresholds Chest Wall 6 months

    More Details

    NCT Number: NCT00858624
    Other IDs: 07/H1004/142
    Study URL: https://clinicaltrials.gov/study/NCT00858624
    Last updated: Sep 29, 2023