Trusted medical expertise in seconds.

Access 1,000+ clinical and preclinical articles. Find answers fast with the high-powered search feature and clinical tools.

Try free for 5 days
Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer.

Beta-2 adrenergic agonists

Last updated: March 25, 2021

Summarytoggle arrow icon

β2 adrenergic agonists are used in pulmonology as bronchodilators, in obstetrics as tocolytic agents, and to manage patients with hyperkalemia. There are both short-acting and long-acting β2 agonists, and their duration of action determines their clinical application. Their effects are achieved through β2 receptor stimulation. Side effects are partially mediated by the β1 receptor and include anxiety and tremor, as well as life-threatening conditions such as ventricular arrhythmias.

  • All β2 adrenergic agonists selectively stimulate β2 adrenergic receptors.
  • Relax bronchial smooth muscle
Pharmacodynamics of β2 adrenergic agonists [1][2]
Characteristic Agent Onset of action Duration of action
Short-acting beta agonists (SABA)
  • Albuterol
  • Fenoterol
  • Reproterol
  • Terbutaline
  • Pirbuterol
  • Levalbuterol
  • 1–5 min
  • 4–6 h
Long-acting beta agonists (LABA)
  • Formoterol
  • 1–5 min
  • ≥ 12 h
  • Salmeterol
  • 30–45 min

Paradoxical bronchospasm may occur!


We list the most important adverse effects. The selection is not exhaustive.

Salmeterol should not be used as monotherapy during an acute asthma attack!


We list the most important contraindications. The selection is not exhaustive.

  • A face mask is recommended for children < 4 years on inhalational therapy.
  1. Ohar JA, Donohue JF. Mono- and Combination Therapy of Long-acting Bronchodilators and Inhaled Corticosteroids in Advanced COPD. Semin Respir Crit Care Med. 2010; 31 (3): p.321-333. doi: 10.1055/s-0030-1254072 . | Open in Read by QxMD
  2. Ejiofor S, Turner AM. Pharmacotherapies for COPD. Clin Med Insights Circ Respir Pulm Med. 2013; 7 : p.CCRPM.S7211. doi: 10.4137/ccrpm.s7211 . | Open in Read by QxMD
  3. Bell DS. Advantages of a third-generation β-blocker in patients with diabetes mellitus. Am J Cardiol. 2004; 93 (9): p.49-52. doi: 10.1016/j.amjcard.2004.01.026 . | Open in Read by QxMD
  4. Viera AJ, Wouk N. Potassium disorders: Hypokalemia and hyperkalemia. Am Fam Physician. 2015; 92 (6): p.487-495.
  5. Lam F, Gill P. β-Agonist Tocolytic Therapy. Obstet Gynecol Clin North Am. 2005; 32 (3): p.457-484. doi: 10.1016/j.ogc.2005.05.001 . | Open in Read by QxMD
  6. Herold G. Internal Medicine. Herold G ; 2014