| Theophylline A dimethylxanthine that occurs in tea leaves. It is a diuretic and central nervous stimulant, with a potency slightly less than that of caffeine. Theophylline is used to prevent and treat wheezing, shortness of breath, and difficulty breathing caused by asthma, chronic bronchitis, emphysema, and other lung diseases. It relaxes and opens air passages in the lungs, making it easier to breathe. Click here for more information | 
