Plasma theophylline concentrations, six minute walking distances, and breathlessness in patients with chronic airflow obstruction.
D001991:Bronchitis / Q000188:drug therapy*; D006801:Humans; D005082:Physical Exertion / Q000187:drug effects; D012129:Respiratory Function Tests; D013806:Theophylline / Q000097:blood / Q000627:therapeutic use*
D013806:Theophylline