Effect of Over-the-counter NSAIDS on Cough Reflex Sensitivity in Patients with Upper Respiratory Tract Infections
brief summary
The goal of this mechanism of disease study is to investigate the effect of flurbiprofen, a non-steroidal anti-inflammatory drug (NSAID), on the cough hypersensitivity associated with upper respiratory tract infections (URTI). The main questions it aims to answer are: * Q1: Does a single treatment with an approved therapeutic dose of flurbiprofen, an NSAID that prevents the production of prostaglandins, acutely reduce objective measures of cough hypersensitivity in participants with URTI? * Q2: Is the effect of flurbiprofen on cough hypersensitivity in URTI related to participant subjective ratings of acute cough severity? * Q3: Is the effect of flurbiprofen on cough hypersensitivity in URTI related to the levels of prostaglandins or other inflammatory markers measurable in upper airway secretions? Participants will be asked to undergo cough challenge testing, complete quality of life questionnaires, and have their nasal fluid, saliva and pharyngeal secretions sampled before and after a single treatment with flurbiprofen in the form of a lozenge or spray. Participants in the comparator arms of the study will instead receive a placebo lozenge or low dose flurbiprofen spray.
detailed description
People with an Upper Respiratory Tract Infection (URTI), for example the common cold, often exhibit heightened sensitivity to stimuli that cause coughing. This heightened sensitivity is thought to contribute to the short-term excessive coughing that accompanies the infection. What causes the heightened sensitivity is not known but may involve inflammation in the throat.
HYPOTHESIS: The investigators hypothesise that in URTI prostaglandins may lead to cough hypersensitivity by either a direct or indirect action on cough nerve fibre endings in the larynx, lowering their activation threshold to cough stimuli.
OVERALL AIM: This study aims to investigate this hypothesis by assessing whether a single treatment with flurbiprofen, an existing over the counter anti-inflammatory drug (NSAID) medication contained in some 'cold and flu remedies' and used to relieve sore throat in URTI, reduces heightened cough sensitivity through a reduction in throat inflammation. The investigators will recruit 120 otherwise healthy male and female adults experiencing an URTI with acute cough for laboratory assessments lasting 5-6 hours.
OBJECTIVES: The primary objective is to assess whether flurbiprofen, in commercially available lozenge or spray formulations, reduces an individual's sensitivity to a cough evoking stimulus by assessing participant responsiveness to inhaled capsaicin. Capsaicin is the naturally occurring 'hot' component of chilli peppers and commonly used to investigate the cough reflex in humans.
The secondary objectives are to assess the effect of flurbiprofen on:
A. subjective measures of cough and urge-to-cough using questionnaires that assess Patient Reported Outcomes (PROs); and, B. the levels of chemical mediators of inflammation present in nasal secretions and saliva, to investigate flurbiprofen's potential mechanism of action.
METHOD: The investigators will test the hypothesis by measuring in participants their cough thresholds, subjective experiences with cough and urge-to-cough, and levels of airway prostaglandins and other inflammatory mediators, before and after a single treatment of flurbiprofen, which blocks the production of prostaglandins.
official title
Effect of Over-the-counter Non-steroidal Anti-inflammatory Treatments on Cough Reflex Sensitivity in Subjects with Upper Respiratory Tract Infection