Stanford University School of Medicine Theophylline (a dimethylxanthine) is a bronchodilator that has been used to treat asthma and chronic obstructive pulmonary disease (COPD) for more than 80 years.

Anti-inflammatory effects are seen with serum theophylline levels <10 mg/l. A higher range of 10–20 mg/l is necessary for bronchodilator effects, but toxic adverse effects become apparent.