Theophylline is a medication commonly used to treat respiratory conditions like asthma and chronic obstructive pulmonary disease (COPD). It works by relaxing the muscles around the airways, making it easier to breathe. Theophylline is often available in pill form or as a liquid, and it can help reduce symptoms like wheezing and shortness of breath. This drug belongs to a class of medications called xanthines, which also includes caffeine and theobromine. While Theophylline can be effective, it requires careful monitoring because its levels in the blood can be affected by various factors, including diet and other medications.