A single high dose of formoterol is as effective as the same dose administered in a cumulative manner in patients with acute exacerbation of COPD.

Several clinical trials have shown that the inhaled beta2-agonists with long-acting properties, formoterol and salmeterol, may be effective in acute exacerbations of chronic obstructive pulmonary disease (COPD). However, there is a great deal of controversy regarding the timing and optimal dose of inhaled beta2-agonists in this pathologic condition. In this double-blind, randomised, crossover study, we have compared the bronchodilating effect and the safety of inhaled formoterol administered via Turbuhaler using either a cumulative dose regimen or the equivalent single dose in 16 patients with acute exacerbations of COPD. On the two consecutive days, the patients received, in a randomised order, each of the following active dose regimens: (A): 9 + 9 + 18 microg of formoterol via Turbuhaler (36 microg cumulative delivered dose) or (B): 36 + 0 + 0 microg of formoterol via Turbuhaler. The three doses on each treatment day were administered at 30-mm intervals, with measurements being made 5 and 30 min after each dose. Contemporaneously, we also measured oxygen saturation by pulse oximetry (SpO2) and pulse rate. Both the high dose and the cumulative one induced a significant bronchodilation expressed as change in FEV1. The difference between the two regimens was significant (P=0.0332) only 60 min after the first inhalation. The trend of FVC and IC was similar to that of FEV1. All treatment regimens were well tolerated and no adverse events were reported. Neither the administration ofthe high dose nor that of the cumulative one modified heart rate in a significant manner. Also they did not influence SpO2. This study indicates that a single high dose offormoterol is as effective as the same dose administered in a cumulative manner in patients with acute exacerbation of COPD.