COMPARISON OF THE EFFECTS OF SALMETEROL AND IPRATROPIUM BROMIDE ON EXERCISE PERFORMANCE AND BREATHLESSNESS IN PATIENTS WITH STABLE CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

To compare the effects of salmeterol, an adrenergic drug, and ipratrop ium bromide, an anticholinergic drug, on breathlessness and gas exchan ge during exercise in patients with chronic obstructive lung disease ( COPD), we performed a progressive treadmill exercise test on 15 patien ts on 3 days (24 h apart), after inhalation placebo, ipratropium bromi de (120 mu g) or salmeterol (50 mu g) in a randomized fashion. Dyspnoe a during exercise was evaluated from the regression slope between Borg scale (BS) scores and distance walked each minute on the treadmill. T he regression was expressed as the distance walked at BS score 5, the threshold load of dyspnoea (TLD) and breakpoint load of dyspnoea. Duri ng and after the exercise, oxygen saturation was monitored by pulse ox ymeter and we measured the lower SaO(2) during exercise and the recove ry time of SaO(2) after exercise. In comparison to placebo inhalation we found the same small but significant improvement in airflow limitat ion after salmeterol or ipratropium inhalation, also the distance walk ed on treadmill increased after bronchodilators. After bronchodilators the magnitude of oxyhaemoglobin desaturation with exercise was simila r to that observed after placebo but the duration of the recovery from sustained SaO(2) desaturation after exercise was shorter to the same extent as after ipratropium or salmeterol. Dyspnoeic sensation, when a ssessed by the TLD and by the distance walked at BS score 5. was decre ased after salmeterol and after ipratropium bromide to a similar exten t. We conclude that the salmeterol, when given in conventional doses; produces significant improvement in the airway obstruction in the reco very of postexercise HbO(2) desaturation and in dyspnoeic sensation in patients with COPD, effects which were similar to those observed afte r inhalation of the anticholinergic agent ipratropium bromide.