The Long-Term Effects of Beta Receptor Agonist Therapy in Relation to Morbidity and Mortality

The treatment of asthma has undergone remarkable changes in the last 30 to 40 years. Despite the development of more specific and effective drugs and improved delivery systems there has been a worldwide trend for asthma morbidity and mortality to increase. Attention has focused on beta agonists and the possibility that they may be implicated in the epidemics of asthma deaths in particular and that they may, paradoxically, be causing a deterioration in asthma control. A relationship between sales of beta agonists and mortality from asthma has been demonstrated for the epidemics of asthma deaths in a number of epidemiological studies. The main concern with beta agonists is the suggestion that when taken regularly they can make asthma worse. When given acutely to subjects with asthma, beta2 agonists provide protection against all constrictor stimuli including exercise, allergen, histamine, and methacholine; the degree of protection is related to the dose, timing, and mode of administration of the drug.