“…However concerns remain over side effects (Harvey et al, 1981) and the possible development of tolerance. The question of tolerance to P2-adrenoceptor agonists has been extensively studied with clear evidence of tolerance as regards heart rate (Barnes and Pride, 1983), metabolic responses (Harvey & Tattersfield, 1982;Jenne etal., 1977), tremor (Prior & Cochrane, 1982) and bronchodilator effects in normal subjects (Larsson et al, 1977), but the majority of studies have failed to detect evidence of bronchodilator tolerance in asthma (Larsson et al, 1977;Nelson et al, 1983;Tattersfield, 1985).…”