Inhaled beta2-agonists and airway responses to allergen.
A series of investigations show that the regular use of inhaled beta2-agonists will increase all aspects of the airway response to allergen. The mechanism of this effect is uncertain; however, it appears to be different from the mechanism that produces tolerance to beta2-agonist effects. One possibility is that the regular use of beta2-agonists might induce a mast cell beta-receptor dysfunction that might make mast cells more prone to release mediators. As a result beta2-agonist use plus allergen exposure might cause more mediator release than does allergen exposure alone. The corollary of this is that beta2-agonist use plus allergen exposure might cause more airway inflammation than does allergen exposure alone. These hypotheses are both testable. I believe that this is a clinically important phenomenon and may well be a major reason for beta2-agonist-induced worsened asthma control. Further investigations are indicated to identify the mechanism and the clinical relevance of the phenomenon.
Cockcroft
D W
DW
Department of Medicine, Royal University Hospital, Saskatoon, Saskatchewan, Canada.
D000249:Adenosine Monophosphate / Q000494:pharmacology; D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives; D000485:Allergens / Q000276:immunology; D001249:Asthma / Q000276:immunology / Q000503:physiopathology / Q000517:prevention & control; D016084:Bronchoconstriction / Q000187:drug effects; D001993:Bronchodilator Agents / Q000009:adverse effects / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004361:Drug Tolerance; D005541:Forced Expiratory Volume; D006801:Humans; D016210:Methacholine Chloride / Q000494:pharmacology; D016032:Randomized Controlled Trials as Topic; D000068299:Salmeterol Xinafoate; D013726:Terbutaline / Q000494:pharmacology; D013997:Time Factors
D000318:Adrenergic beta-Agonists; D000485:Allergens; D001993:Bronchodilator Agents; D016210:Methacholine Chloride; D000249:Adenosine Monophosphate; D000068299:Salmeterol Xinafoate; D013726:Terbutaline; D000420:Albuterol