Safety of formoterol Turbuhaler1 at cumulative dose of 90 mg in patients with acute

ABSTRACT: This study compared the safety of formoterol (Oxis1 Turbuhaler1; 90 mg delivered dose; 120 mg metered dose) with terbutaline (Bricanyl1 Turbuhaler1; 10 mg), in patients with acute bronchoconstriction. Forty-eight patients (31 females) with a mean age of 45 yrs, were randomized into two parallel groups (double-blind design). Mean baseline forced expiratory volume in one second (FEV1) was 0.98 L (33 % of predicted normal). Study drugs were administered on six occasions during 3 h (formoterol 4.5 mg or terbutaline 0.5 mg?inhalation-1, 20 inhalations). Patients received intravenous prednisolone after 1.5 h and oxygen during the first 3 h. Pulse rate, serum potassium, 12-lead electro-cardiogram (ECG), Holter ECG, arterial blood gases and FEV1 were assessed during 12 h after the first dose. Four patients (one formoterol, three terbutaline) discontinued. The 12-h mean values of serum potassium decreased from 4.02 to 3.89 mmol?L-1 for formoterol and from 4.22 to 3.76 mmol?L-1 for terbutaline. Mean 12-h pulse rate was significantly (pv0.01) higher in the terbutaline group (101.7 beats per minute (bpm)) than in the formoterol group (93.5 bpm). No individual patient value was considered clinically important or alarming. FEV1 improved in both groups but with no statistically significant difference between treatments. Oxis1 Turbuhaler1 (90 mg) was at least as safe and well tolerated as terbutaline (110 mg) in patients with acute bronchoconstriction