Theophylline is primarily used as what type of medication?

Theophylline is primarily used as a bronchodilator, which means it works by relaxing and expanding the airways in the lungs. This action helps relieve symptoms associated with respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). Theophylline functions by inhibiting phosphodiesterase enzymes, leading to increased levels of cyclic AMP in the cells, which results in smooth muscle relaxation and bronchodilation.

In the context of other medication types, such as antibiotics, corticosteroids, and antihistamines, they serve different purposes. Antibiotics are designed to combat bacterial infections, corticosteroids reduce inflammation across various conditions, and antihistamines help relieve allergy symptoms. Each of these medications has a distinct mechanism of action and therapeutic use, which further confirms the role of theophylline as a bronchodilator.