A 3-month comparison of formoterol with terbutaline via turbuhaler.: A placebo-controlled study

Background and aim: Oxis Turbuhaler is a new dry powder formulation of long-acting beta(2)-agonist formoterol. This study compared the efficacy and safety of regular use of the long-acting beta(2)-agonist formoterol and the short-acting terbutaline for 3 months in patients with asthma. Method: After 1-week run-in, 343 patients received either formoterol 12 mu g bid (F) (delivered dose of 9 mu g), terbutaline 500 mu g qid (T) or placebo qid, in a parallel-group, double-blind, randomized manner. They had a mean of 61% of predicted forced expiratory volume in 1 second (FEV1) and a mean reversibility of 26%. Eighty-nine percent used inhaled corticosteroids. Results: During run-in mean morning peak expiratory flow (PEF L/min) for F was 366 and 348 for T, and 344 for placebo (P). The F group improved morning PEF significantly compared with P (P = .0022) and T (P = .0001). Changes from run-in were +18, -1.5, and +5 L/min after F, T, and P, respectively. The F group was statistically significantly better than P and T in increasing evening PEF and in reducing night-time asthma. The F and T statistically significantly reduced the use of rescue medication compared with P. The bronchodilating response to the study drug and to an additional 1.25 mg terbutaline was of the same magnitude before and throughout the study. No statistically significant treatment-by-time interaction was observed (P > .20). There were no adverse effects of clinical relevance. Conclusion: Formoterol Turbuhaler, 12 mu g bid, was more effective than terbutaline Turbuhaler, 0.5 mg qid, and placebo. Regular use of formoterol or terbutaline did not significantly influence the response to additional inhalation of terbutaline.