What It Is
Theophylline belongs to a class of medicines called methylxanthines, which are related to caffeine. It is taken by mouth as tablets or capsules and can also be given by injection in hospitals.
What It's Used For
Theophylline is generally used to treat long-term breathing conditions such as asthma and chronic obstructive pulmonary disease (COPD). It helps reduce wheezing, chest tightness, and shortness of breath.
How It Works
Theophylline relaxes the smooth muscles around the airways, which widens them and makes breathing easier. It does this partly by blocking an enzyme called phosphodiesterase and partly by blocking adenosine receptors. It also has a mild anti-inflammatory effect. The gap between an effective dose and a harmful dose is small, so doctors often check blood levels during treatment.
History and Regulatory Status
Theophylline occurs naturally in tea leaves and was first extracted in the late 1800s. It became a standard treatment for asthma in the twentieth century. Its use has fallen as inhaled medicines have become the preferred option, but it remains available as a generic prescription medicine, especially where other treatments are limited or costly.