THEOPHYLLINE SERUM CONCENTRATION AND THERAPEUTIC EFFECT IN SEVERE ACUTE BRONCHIAL OBSTRUCTION - THE OPTIMAL USE OF INTRAVENOUSLY ADMINISTERED AMINOPHYLLINE

Abstract

In 20 patients with acute exacerbation of bronchial obstruction, the therapeutic effect of high (20 mg/l) and low (10 mg/l) serum concentrations of theophylline was compared in a double-blind randomized study. The theophylline dose, administered as a continuous aminophylline infusion, was individually adjusted by means of repeated measurements of serum concentrations. At 28 h after starting therapy the high concentration group showed a significantly greater improvement in pulmonary function as assessed by FEV, [1-s forced expiratory volume] (0.57 .+-. 0.52 l (mean .+-. SD) vs. 0.1 .+-. 0.18 l, P < 0.01) and FVC [forced vital capacity] (1.0 .+-. 0.65 l vs. 0.01 .+-. 0.66 l, P < 0.02). As a measure of the overall clinical improvement, the time during which i.v. therapy was required was also shorter in the high-dose group (61.7 .+-. 25.8 h vs. 116 .+-. 49.7 h, P < 0.02). The occurrence of side-effects in the 2 groups was not significantly different. In patients with severe acute bronchial obstruction, serum theophylline concentrations .apprx. 20 mg/l seemed to offer a definite therapeutic advantage. Routine serum concentration measurements and the use of accurate infusion devices for optimal dose adjustment may be justified.