Two New ?2-Adrenoceptor Agonists, D-2343 and QH 25, Studied in Asthmatic Patients

Abstract

New .beta.2-adrenoceptor agonists, D-2343 [N-[3-(2-methoxyphenyl)-1,1-dimethylpropyl]-1-(p-hydroxy phenyl) ethanolamine] and QH 25 [3-(4-methoxybenzylamino)-4-hydroxy-.alpha.-(tert-butyl aminomethyl)benzyl alcohol], were studied in asthmatic patients. D-2343 (4 i.v. cumulatively increasing doses, 0.21-6.3 .mu.g/kg per min) and i.v. terbutaline (4 cumulative doses 0.07-2.1 .mu.g/kg per min) were single-blindly compared in a randomized crossover study in 8 asthmatics. D-2343 is an effective .beta.2-adrenoceptor agonist with 5-6 times lower potency than terbutaline. The tremor-inducing effect of D-2343 was the same as that of terbutaline when the same degree of bronchodilation was obtained. The effect of QH 25 (0.25, 0.75 and 2.25 mg cumulatively) administered orally, was single-blindly compared with the effect of oral salbutamol (2, 6 and 18 mg) in a randomized crossover study in 8 asthmatics. QH 25 was an effective .beta.2-adrenoceptor stimulant, .apprx. 12 times more potent than salbutamol. The tremor-inducing capacity was the same as for salbutamol when quipotent bronchodilating doses were studied.