Lidocaine: Effect of Lidocaine in Chronic Cough

People cough in order to clear their airways. Most coughs are caused by viruses and settle down by themselves, but some people develop persistent coughing which can be anywhere from 8 weeks to several years. This is called chronic cough. People with chronic cough find the symptom distressing and it can have a major impact on their quality of life. Patients with chronic cough often report a sensation at the back of their throat which makes them feel an urge to cough. There is some evidence that Lidocaine (an anaesthetic used during medical procedures) can suppress a person's cough when given to patients via a nebuliser (a machine that turns liquid into a fine mist). It is currently unknown whether using a local anaesthetic, such as Lidocaine, in the form of a throat spray would successfully suppress a person's cough. A throat spray would be an easier treatment option in chronic cough patients. Thus, the investigators research aims to compare cough rates, severity and urge to cough scores between Lidocaine throat spray and nebulised Lidocaine.