Clinical and Experimental Allergy, 1992, Volume 22, pages 659-664
EDITORIAL
The j5-agonist controversy: fact or fiction? Introduction
Inhaled j9-agonists have been used for three decades as first-line bronchodilator therapy in patients with asthma. However, recent concerns regarding their safety, particularly with respect to fenoterol, have resulted in a reappraisal of their role as reliever drugs. Inhaled fenoterol has been implicated as being a possible contributing factor to the rise in asthma mortality in New Zealand since the late 1970s, on the basis of case control studies [1-3], although the latter have received considerable methodological criticism. In vivo studies have shown that high doses of inhaled fenoterol cause greater cardiac sequelae than salbutamol [4,5], and not surprisingly it has been speculated that this may account for the epidemiological data. The findings of Sears et al. [6] showing that regular inhaled fenoterol might worsen asthmatic disease control have confounded concerns regarding /?-agonist safety. The recent availability of the novel long-acting drugs such as salmeterol have also heightened awareness about the use of j3-agonists in asthma. In this article I hope to clarify some contentious issues in the j8-agonist debate, because there is a danger that we may be casting aside a relatively safe and effective class of reliever therapy. Two important issues will be addressed. Firstly, the selectivity of fenoterol in vivo and the role of cardiac /J2-receptors, Secondly, the effects of /^-agonists on bronchial hyperreactivity and disease control in asthma, and the role of the novel long-acting inhaled P2agonists.
Selectivity and cardiac ^2-
EDITORIAL
The j5-agonist controversy: fact or fiction? Introduction
Inhaled j9-agonists have been used for three decades as first-line bronchodilator therapy in patients with asthma. However, recent concerns regarding their safety, particularly with respect to fenoterol, have resulted in a reappraisal of their role as reliever drugs. Inhaled fenoterol has been implicated as being a possible contributing factor to the rise in asthma mortality in New Zealand since the late 1970s, on the basis of case control studies [1-3], although the latter have received considerable methodological criticism. In vivo studies have shown that high doses of inhaled fenoterol cause greater cardiac sequelae than salbutamol [4,5], and not surprisingly it has been speculated that this may account for the epidemiological data. The findings of Sears et al. [6] showing that regular inhaled fenoterol might worsen asthmatic disease control have confounded concerns regarding /?-agonist safety. The recent availability of the novel long-acting drugs such as salmeterol have also heightened awareness about the use of j3-agonists in asthma. In this article I hope to clarify some contentious issues in the j8-agonist debate, because there is a danger that we may be casting aside a relatively safe and effective class of reliever therapy. Two important issues will be addressed. Firstly, the selectivity of fenoterol in vivo and the role of cardiac /J2-receptors, Secondly, the effects of /^-agonists on bronchial hyperreactivity and disease control in asthma, and the role of the novel long-acting inhaled P2agonists.
Selectivity and cardiac ^2-
