Bronchodilating effects of cumulative doses of formoterol from a novel multi-dose inhaler (Airmax®)

The bronchodilating properties of formoterol from a novel multi-dose inhaler, Airmax® 6μg and from a single-dose dry powder inhaler Foradil® Aeroliser® 12μg were investigated in 31 adult asthmatics with FEV1≥60% predicted and a reversibility ≥12%. Patients received on a single day four doses of formoterol: cumulative dose 6, 12, 24 and 48μg from Airmax, or 12, 24, 48 and 96μg from Aeroliser®. The mean FEV1 (SD) from baseline to 1h after the final cumulative dose increased by 0.81l from 2.62 (0.58) to 3.43l (0.70) with Airmax® and by 0.85l from 2.65 (0.60) to 3.5l (0.68) with Aeroliser®. All 90% CIs for all four dose comparisons were within the equivalence range ±0.1l. There was a higher incidence of hypokalaemia and hyperglycaemia at highest doses during treatment with the Aeroliser® than with Airmax®. In conclusion, formoterol delivered from Airmax® provides a dose-dependent bronchodilating effect which is similar to that obtained by Aeroliser® at double the dose.