Theophylline belongs to which drug class?

• A. Methylxanthine Derivatives
• B. Beta-adrenergic agonists
• C. Corticosteroids
• D. Anticholinergics

Answer: (A)

Theophylline is a methylxanthine derivative. This family includes caffeine and theobromine and is known for bronchodilation. The main action in the airways comes from inhibiting phosphodiesterase, which raises cAMP in bronchial smooth muscle and leads to relaxation. It also can block adenosine receptors, contributing to bronchodilation. Because of its narrow therapeutic window and potential interactions, it’s used with careful monitoring. Other listed classes work by different mechanisms—beta-adrenergic agonists stimulate beta-2 receptors for relaxation, corticosteroids reduce inflammation, and anticholinergics block acetylcholine to decrease airway constriction—so theophylline fits best with methylxanthine derivatives.