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

A new beta 2-adrenoceptor agonist D2343 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 eight asthma patients. We found that 5 mg of D2343 was equipotent to 5 mg terbutaline in bronchodilatory effect measured with FEV1. The duration was longer with an increased bronchodilation (P less than 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 less than 0.05). Thus, this study shows that inhaled D2343 has a longer bronchodilating effect than terbutaline.