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TWICS - Theophylline with Inhaled CorticoSteroids

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease affecting approximately 3 million people in the UK.  It is the fifth leading cause of death in the UK and costs the NHS approximately £1 billion annually.  Exacerbations of COPD are associated with accelerated rate of lung function decline, reduced physical activity, reduced quality of life, increased mortality and increased risk of other illnesses such as acute myocardial infarction and stroke. 

Usual treatment for COPD is inhaled corticosteroids.  Small studies have shown that giving patients theophylline at a low dose can increase the sensitivity of their airway to the effects of inhaled corticosteroids – and thus make the inhaled corticosteroids work better. 

In the TWICS study, we aim to determine whether adding low dose oral theophylline to inhaled corticosteroid therapy in patients with COPD reduces the risk of exacerbation, is cost effective to the NHS, improves quality of life and lung function and reduces mortality.  To do this, we will compare the effects of low dose theophylline against the effects of a placebo ‘dummy treatment’, which looks like the genuine medicine but contains no active ingredient.

We will invite people with COPD to take part in our study.  If they agree, we will allocate them to receive low-dose theophylline or placebo for 12 months.  Half of the participants in the study will take low-dose theophylline and half of the participants will take placebo.  We aim to recruit 1424 people with COPD into our study.

We will follow-up study participants after 6 and 12 months to find out how they are getting on and whether they have had any exacerbations of their COPD.   A summary of the study can be found here.  You can read more about the study here

Analysis of the study results is ongoing and we will report results in 2018.

The final data cut for analysis was taken on 22 November 2017. 

Staff at research sites can no longer amend or enter data on the study website (log-ons have been disabled) - please contact the trial office ( with any corrections to data or additional data. 




The Health Services Research Unit is funded by the Chief Scientists Office of the Scottish Government Health and Social Care Directorates