Bronchial Hyper-responsiveness in Reflux Cough

Inclusion Criteria: * Positive methacholine challenge test PC20 less than 4mg/ml (Can be previously documented in patients notes within last 4weeks) * Written informed consent * Patients with a history of chronic cough (at least 3 months duration), and associated symptoms of gastro-oesophageal reflux * Male and female subjects of at least 18 yrs of age * Subjects able to perform satisfactory FEV1 manoeuvres * Subjects able to understand the study and co-operate with the study procedures * Subjects who consent to their general practitioner (GP) being informed of their study participation Exclusion Criteria: * has had a heart attack in the last three months * suffers from angina, hypertension or ischaemic heart disease * has epilepsy for which he/she is taking medication * FEV1\< 60% predicted * FEV1\<1.6L * Female subjects who are pregnant, or lactating, or who are of child bearing potential but are not using contraceptive measures * Suffering from any concomitant disease which may interfere with study procedures or evaluation. * A lower respiratory tract infection 4 weeks prior to entry on to study * Participation in another study (use of investigational product) within 30 days preceding entry on to study. * Alcohol or drug abuse * Use of opiates to treat cough 1 week prior to enrollment * Subjects who are taking Angiotensin Converting Enzymes (ACE) inhibitors. * Subjects who have significant pathology on most recent chest X-Ray. * Inability to understand the procedures and the implications of a challenge test * Patients already taking or have taken in last 4 weeks PPI and H2 receptor antagonist (full acid suppression treatment