A New β2‐Adrenoceptor Agonist – D2343 – with Long Duration

Abstract
A new .beta.2-adrenoceptor agonist S2343 has been shown in a human i.v., study to be less potent than terbutaline. Animal experiments showed an increased affinity to lung tissue and a longer bronchodilating effect than terbutaline when inhaled. In a randomized single-blind, crossover comparison, 2.5 and 5 mg D2343 and 5 mg terbutaline were inhaled by 8 asthma patients. A total of 5 mg of S2343 was equipotent to 5 mg terbutaline in bronchodilatory effect measured with FEV1 [forced expiratory volume in 1 second]. The duration was longer with an increased bronchodilation (P < 0.01) 6 h after D2343 inhalation compared with terbutaline. The mean fall in FEV1 3-6 h after inhalation was significantly greater with terbutaline than with D2343 (P < 0.05). Thus, inhaled D2343 has a longer bronchodilating effect than terbutaline.