grant was withdrawn no financial support to conduct the study.

This is a parallel group, double-blind, placebo controlled, multi-centre, randomised trial.

60 patients to be included who are adult patients admitted to hospital with a clinical diagnosis of acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD). Acute exacerbation of COPD will be defined as sustained worsening of the patient's condition with an increase in cough and one or more of dyspnoea, sputum volume or sputum purulence, necessitating a change in regular medication.

The primary objective of this study is to evaluate the effectiveness of standard care plus erdosteine in reducing hourly cough (24 hour cough recording using automated cough recorder) measured from baseline (Day 0) and at Day 5 of treatment, compared with standard care plus placebo.

Inclusion Criteria:

• Male/females aged between 40-80 years
• Previous diagnosis of COPD
• Acute exacerbation of COPD requiring treatment with antibiotics and/or corticosteroids
• Symptoms of increased breathlessness, cough, sputum volume or sputum purulence
• Acute exacerbation of COPD hospitalised within 24hrs of study participation.
• On a stable therapeutic regimen for COPD for 8 weeks prior to inclusion
• Known history of cigarette smoking at least 10 pack yrs
• Willing and able to comply with study procedures
• Able to provide written informed consent to participate

Exclusion Criteria:

• Acute exacerbation of COPD within 8 weeks prior to inclusion
• Arterial blood gas on admission < pH 7.26
• Currently on treatment with mucolytics
• Patients suffering from post nasal drip, or gastro-oesophageal reflux disease
• Clinically significant or unstable concurrent disease e.g. left ventricular failure, diabetes mellitus
• On long-term oxygen therapy
• Known or suspected hypersensitivity to erdosteine