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World J Respirol. Nov 28, 2015; 5(3): 199-206
Published online Nov 28, 2015. doi: 10.5320/wjr.v5.i3.199
β2-adrenoceptor in obstructive airway diseases: Agonism, antagonism or both?
Daniel WS Tan, Jyi Lin Wong, Siew Teck Tie, John A Abisheganaden, Albert YH Lim, WS Fred Wong
Daniel WS Tan, WS Fred Wong, Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore 117600, Singapore
Jyi Lin Wong, Siew Teck Tie, Respiratory Unit, Department of Medicine, Sarawak General Hospital, 93586 Kuching, Malaysia
John A Abisheganaden, Albert YH Lim, Department of Respiratory and Critical Care Medicine, Tan Tock Seng Hospital, Singapore 308433, Singapore
WS Fred Wong, Immunology Program, Life Science Institute, National University of Singapore, Singapore 119077, Singapore
Author contributions: All authors equally contributed to the writing of the review article.
Supported by NMRC/CBRG/0027/2012 from the National Medical Research Council of Singapore (in part); and by NUHS Seed Fund R-184-000-238-112.
Conflict-of-interest statement: There is no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. WS Fred Wong, Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, 16 Medical Drive, MD3 #04-01, Singapore 117600, Singapore. phcwongf@nus.edu.sg
Telephone: +65-65163266 Fax: +65-68737690
Received: May 28, 2015
Peer-review started: May 28, 2015
First decision: August 4, 2015
Revised: September 1, 2015
Accepted: October 1, 2015
Article in press: October 8, 2015
Published online: November 28, 2015
Abstract

Obstructive airway disease is a complex disease entity including several maladies characterized by bronchoconstriction and abnormal airway inflammation. Reversing bronchoconstriction leads to symptomatic relief and improvement in quality of life, both in reversible (bronchial asthma) and partially reversible (chronic obstructive airway disease) obstructive airway diseases. β2-adrenoceptor expressed in human airway is the main β-receptor subtype, and its activation in airway smooth muscle cells leads to bronchodilatation. Drugs targeting β-adrenoceptors have been around for many years, for which agonists of the receptors are used in bronchodilation while antagonists are used in cardiovascular diseases. This review article summarizes the effect and usage of β2-agonist in obstructive airway disease, addressing the benefits and potential risks of β2-agonist. The article also looks at the safety of β-blocker usage for cardiovascular disease in patients with obstructive airway disease. There is also emerging evidence that non-selective β-blockers with inverse agonism ironically can have long-term beneficial effects in obstructive airway disease that is beyond cardiovascular protection. Further trials are urgently needed in this area as it might lead to a dramatic turnaround in clinical practice for obstructive airway diseases as has already been seen in the usage of β-blockers for heart failure.

Keywords: β-adrenoceptors, β2-agonist, β-blocker, Inverse agonist, Heart failure, β-arrestin

Core tip: This review summarizes the effect and usage of β2-agonist in obstructive airway disease, addressing the benefits and potential risks of β2-agonist. The review also looks at the safety of β-blocker for cardiovascular disease in patients with obstructive airway disease. There is also emerging evidence that non-selective β-blockers with inverse agonism ironically can have long-term beneficial effects in obstructive airway disease beyond cardiovascular protection. Further trials are urgently needed in this field as it might lead to a dramatic turnaround in clinical practice for obstructive airway diseases as has already been seen in the usage of β-blockers for heart failure.