Comparison of Bronchodilator Effects of Fenoterol/lpratropium Bromide and Salbutamol in Patients with Chronic Obstructive Lung Disease

A double-blind, randomized cross-over trial was carried out in 24 patients with chronic airflow obstruction. The patients were required to demonstrate a minimum 15% absolute increase in forced expiratory volume (FEV1) after a standard dose (0.4 mg) of fenoterol (F). On a separate occasion the effect of ipratropium bromide (IB; 0.04 mg) on FEV1 was tested also; according to the increase in FEV1 the patients were grouped into IB responders (delta FEV1 > 15%) and IB nonresponders (delta FEV1 < 15%). Two puffs of F/IB (0.1 mg/0.04 mg), salbutamol (S; 0.2 mg) and placebo (P) were given by metered-dose inhaler at the same time of the day on three different occasions. FEV1 and specific airway resistance (sRaw) were assessed before and at specific intervals following inhalation. The results showed that F/IB and S produced similar maximal increases in FEV1 (delta FEV1 32% for F/IB and 31% for S) and decreases in sRaw (delta sRaw 24% for F/IB and 21% for S). These effects were significantly different both from baseline values and from P. FEV1 was still significantly different 8 h after inhalation from P in the F/IB group, but not in the group that received S. The effect of IB on FEV1 in the pretest was compared with the subsequent response to F/IB. In IB responders F/IB seemed to produce slightly more effective bronchodilation. Side effects were minimal and clinically insignificant. In conclusion, F/IB, with its ability to effect sustained bronchodilation without adverse side effects, is a viable alternative to a monotherapy in chronic obstructive pulmonary disease.