A DOSE-RESPONSE STUDY WITH FORMOTEROL TURBUHALE(R) AS MAINTENANCE THERAPY IN ASTHMATIC-PATIENTS

The aim of this randomized, double-blind, parallel group study was to determine the lowest effective dose of 6, 12 and 24 mu g formoterol fu marate dihydrate Turbuhaler b.i.d. compared with placebo. The 4 week t reatment was preceded by a 1 week run-in period. Morning peak expirato ry flow (PEF) before intake of the study drug was the primary variable . Patients recorded PEF, prior to and 15 min after intake of the study drug (immediate response), asthma symptoms, and use of rescue medicat ion morning and evening, Of 221 patients (71 females and 150 males), 1 94 were included in the efficacy per protocol (PP) analysis; mean age 47 yrs, mean forced expiratory volume in one second (FEV1) 2.01 L (58% of predicted), mean FEV1 reversibility 27% at entry. Ninety percent u sed inhaled steroids. Compared with placebo, 6 mu g formoterol b.i.d. was found to be the lowest effective dose in the morning (p=0.008) and evening (p=0.0041) PEF. The mean increases in PEF were 22 and 23 L . min(-1) respectively, compared with placebo. After 6 mu g formoterol, the mean immediate increase in morning PEF was 42 L . min(-1) compared to an increase of only 9 L . min(-1) after placebo (p<0.0001). All do ses produced a statistically significant decrease in asthma symptoms, day and night,and the need for rescue medication at night. All doses w ere well-tolerated. In conclusion, the lowest effective dose in this s tudy was formoterol Turbuhaler 6 mu g b.i.d.