Effect of Theophylline as Adjunct to Inhaled Corticosteroids on Exacerbations in Patients With COPD: A Randomized Clinical Trial.
JAMA. 2018 Oct 16;320(15):1548-1559. doi: 10.1001/jama.2018.14432.
JAMA. 2018.
PMID: 30326124
Free PMC article.
Clinical Trial.