COMPARISON OF BRONCHODILATOR EFFECTS OF SAME AMOUNTS OF TERBUTALINE AEROSOL GIVEN AS A SINGLE OR IN DIVIDED DOSES

Abstract

Inhalation of 0.5 mg of terbutaline, given as a single dose or as 2 immediately consecutive doses of 0.25 or 4 consecutive doses 0.125 mg, produced the same degree of effective bronchodilation in 12 asthmatic patients at all measured intervals from 30 s-4 h after administration. Each treatment regimen produced equivalent improvement in FVC [forced vital capacity], FEV, [forced expiratory volume in 1 s], MMEF [maximal mid-expiratory flow rate], MMV [maximum voluntary ventilation], PEFR [peak expiratory flow rate], Vmax 50% VC [flow rate at 50% of vital capacity] and Vmax 25% VC [flow rate at 25% of vital capacity]. The most sensitive indicators were MMEF and Vmax 50% VC. No significant side-effects were encountered with this dosage and route of administration. In patients who are trained in the proper use of metered dose dispensers a single 0.5 mg inhalation may be sufficient to deliver the required dose to obtain an effective and safe therapeutic response.