Formoterol (OXIS ®) Turbuhaler ® as a rescue therapy compared with salbutamol pMDI plus spacer in patients with acute severe asthma

Abstract

Formoterol has a similar onset of effect to salbutamol but a prolonged duration of action. However, the relative efficacy of the two drugs in acute severe asthma is not known. This double-blind, double-dummy study compared the safety and efficacy of the maximum recommended daily dose of formoterol and a predicted equivalent dose of salbutamol in 88 patients presenting to the emergency department with acute severe asthma. Patients were randomized to formoterol 54 μg via Turbuhaler ® or salbutamol 2400 μg via pressurized metered dose inhaler (pMDI) plus spacer in three equal doses over 1 h. Following the full dose, mean FEV 1 at 75 min increased by 37% for formoterol and 28% for salbutamol ( P=0.18). The maximum increase in FEV 1 over 4 h was significantly greater with formoterol compared with salbutamol (51% vs. 36%, respectively P<0.05) and formoterol was as effective as salbutamol at improving symptoms and wellbeing. Both treatments were well tolerated. Formoterol caused a greater decrease in serum potassium (difference –0.2 mmol/l). In severe acute asthma, bronchodilator therapy with high-dose (54 μg) formoterol Turbuhaler provided equally rapid improvements in lung function of greater magnitude over 4 h than high-dose (2400 μg) salbutamol pMDI plus spacer.