Bronchodilators Explained: Beta-2 Agonists, Anticholinergics, and Methylxanthines
Respiratory Pharmacology • Educational

Bronchodilators, Made Simple

A clear, modern overview of bronchodilators—how they relax airway smooth muscle, where they’re used, and what to watch for.

This article is for education only and not a substitute for professional medical advice.

In this guide:

Beta-2 Agonists (suffix: -terol)

Beta-2 agonists stimulate β2 receptors in airway smooth muscle → bronchodilation and improved airflow.

SABAs (Short-Acting)

LABAs (Long-Acting)

  • Maintenance therapy for asthma and COPD
  • Example: salmeterol
  • Often combined with inhaled corticosteroids for long-term control

Anticholinergics (suffix: -tropium)

Anticholinergics block muscarinic receptors, reduce mucus production, and relax bronchial smooth muscle.

Short-acting

Long-acting

Methylxanthines (suffix: -phylline)

Methylxanthines inhibit phosphodiesterase → higher cAMP → bronchodilation and decreased airway responsiveness.

  • Main example: theophylline (therapeutic drug monitoring is often required)
  • Consider caffeine sensitivity—these are xanthine derivatives

Education Pearls

  • Use inhalers in the prescribed order when combined with steroids.
  • Rinse the mouth after steroid inhalers to lower the risk of thrush.
  • Know your “reliever” (often a SABA) vs. “controller” (LABA ± inhaled steroid) therapy.

Common Side Effects

  • tachycardia, palpitations, tremor/shakiness
  • nervousness, dizziness, insomnia
  • dry mouth; anticholinergics: blurred vision, constipation, reduced secretions
  • For theophylline: monitor for toxicity (dysrhythmias, seizures)
  • Report persistent side effects to a clinician

Cited Keywords & Referral Links

Each keyword below links to a dedicated page on gyathshammha.com.

Bottom line

Bronchodilators improve airflow by relaxing airway smooth muscle. Short-acting agents (like albuterol) rescue acute symptoms, while long-acting therapies (salmeterol, tiotropium) help maintain control—often alongside inhaled steroids. Theophylline is an option in select cases with careful monitoring.

Disclaimer: This content summarizes common educational points reflected in an infographic and general pharmacology texts. It is not medical advice. Always consult a licensed clinician for diagnosis or treatment decisions.