Acute cardiovascular effects of salmeterol in subjects with stable bronchial asthma

The airway response and cardiovascular effects of salmeterol (SM) and salbutamol (SB) given as a single dose from metered-dose inhalers were studied in 10 patients with mild asthma. In a double-blind, randomized, cross-over, placebo-controlled study, the subjects received SM 100 micrograms (four puffs, 25 micrograms per actuation), SB 200 micrograms (four puffs, 50 micrograms per actuation) or placebo (P) (four puffs). SM caused a greater and longer lasting increase of peak expiratory flow rate (PEFR) value than SB and P. There was no significant difference either with P or the study drugs in heart rate, PR interval, QT interval corrected for heart rate (QTc), incidence of ventricular and supraventricular ectopics, and in echocardiogram evaluation. These findings show that at dosages based on those used in clinical practice salmeterol causes cardiovascular effects comparable to those induced by salbutamol and confirm the favourable cardiac safety profile of this drug.