It is a derivative of m-hydroxyproterenol, which has a strong excitatory effect on the receptor, and the therapeutic amount has less effect on the 1 receptor in the heart. The bronchodilation effect induced by oral administration of 5mg was similar to that of 5mg MHT, with few cardiac side effects. The increased dose still enhanced the bronchiectasis, but the incidence of cardiovascular side effects and tremor was also increased. Inhalation of one dose of 300 to 400 g of this product may produce long-lasting bronchiectasis, with fewer side effects. Inhalation of more dose does not enhance the efficacy, but rather increases the side effects. Most observations indicated that the product was as effective as albuterol at the same dose inhaled. Oral absorption from the gastrointestinal tract quickly, 2 hours after the peak blood concentration, lasting for 6 to 8 hours. The number of inhaling air mist is effective in a minute, 1 to 2 hours to reach the peak effect, at least lasting 4 to 5 hours.

[Pharmacological action] : This product is a selective receptor excitant with stronger and longer duration of bronchodilating smooth muscle than isoprenol and albuterol. This product has anti-allergic effect, can inhibit mast cells to release histamine, inhibit passive skin allergic reaction and experimental asthma. In addition, this article still has stimulative respiratory tract cilia movement, increase the effect such as the clearance of respiratory tract mucous.