, results from a large trial funded by the United Kingdom found.
Doug Brunk/MDedge News
Dr. David B. Price
“Globally, theophylline was used for decades as a bronchodilator,” one of the study authors, David B. Price, MB BChir, said at an international conference of the American Thoracic Society. “The problem is theophylline has a narrow therapeutic index, it requires some blood monitoring, and it has been replaced by more effective inhaled bronchodilators. However, there has been a lot of discussion about whether low-dose theophylline has anti-inflammatory effects on its own and whether it increases sensitivity to inhaled steroids in COPD.”
According to the 2018 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, there is “limited and contradictory evidence regarding the effect of low-dose theophylline on exacerbation rates,” and its clinical relevance has “not yet been fully established.” Dr. Price, a professor of primary care respiratory medicine at the University of Aberdeen, United Kingdom, and his associates hypothesized that the addition of low-dose theophylline to inhaled steroid therapy in COPD would reduce the risk of moderate to severe COPD exacerbations after one year of treatment. “If it worked, it would be wonderful; it would save the National Health Service a fortune,” he said.
In a government-funded trial known as Theophylline With Inhaled Corticosteroids (TWICS), people aged 40 years and older with COPD on a drug regimen including inhaled corticosteroids with a history of at least two exacerbations treated with antibiotics and/or oral corticosteroids in the previous year were recruited in 121 U.K. primary and secondary care sites from January 2014 through August 2016. They were randomized to receive low-dose theophylline or placebo for one year. Theophylline dose (200 mg once/twice a day) was determined by ideal body weight and smoking status. Primary outcome was the number of participant-reported exacerbations in the one year treatment period treated with antibiotics and/or oral corticosteroids. Participants were assessed six and 12 months after randomization. The study was powered to detect a 15% reduction in exacerbations and aimed to recruit 1,424 participants.
In all, 1,578 people were randomized: 791 to theophylline and 787 to placebo. Of these, primary outcome data were available for 98% of participants: 772 in the theophylline group and 764 in the placebo group, which amounted to 1,489 person-years of follow-up data. The mean age of patients was 68 years, 54% were male, 32% currently smoked, 80% were using inhaled corticosteroids/long-acting beta 2-agonists/long-acting muscarinic agents, and their mean FEV1 was 51.7% predicted.
Slightly more than one-quarter of study participants (26%) ceased study medication. Dr. Price said that this was balanced between the theophylline and placebo groups and mitigated by over-recruitment and a high rate of follow-up.
He reported that there were 3,430 moderate to severe exacerbations: 1,727 in the theophylline group and 1,703 in the placebo group. The mean number of exacerbations in participants allocated to theophylline and placebo groups were essentially the same: 2.24 vs. 2.23. However, there were a fewer number of exacerbations that required hospitalization in the theophylline group, compared with the placebo groups (0.17 vs. 0.24, for an adjusted rate ratio of 0.72). Dr. Price was quick to point out that this finding applied to a relatively small number of study participants, about 3% overall.