OBJECTIVE AND SUBJECTIVE BRONCHODILATION OVER 12 HOURS AFTER INHALED FORMOTEROL - INDIVIDUAL-RESPONSES

The aim of the present study was to compare the duration of bronchodil ation obtained with 12 mu g formoterol and 24 mu g formoterol with tha t of 200 mu g salbutamol over 12 hr. Thirteen stable asthmatics (mean age 59 years, asthma duration 7 years, mean FEV(1) 56% predicted, and reversibility to beta-adrenoceptor stimulation 36%) were studied in a double-blind crossover study. Lung function test (FEV, and FVC), heart rate, tremor, and subjective effects were recorded before and 30 min after the test doses and every hour up to 12 hr. The test doses were r andomized and given double-blindly as two puffs using a spacer. The me dian duration of effect, defined as time when FEV(1) fell below 20% th e maximum bronchodilating capacity, was longer than 12 hr for both for moterol doses, whereas it was 7 hr for salbutamol (p < 0.01). No diffe rence between the two doses of formoterol was seen. The median of the patients' subjective evaluation of the duration of effect was 12 hr, m ore than 12 hr for 12 and 24 mu g formoterol, respectively, and 8 hr f or salbutamol (p < 0.01). Only 1 patient needed rescue medication on t he 2 formoterol days. However, 6 patients inhaled rescue medication du ring treatment with salbutamol. There were no differences with regard to heart rate, blood pressure, subjective tremor, or palpitations. For moterol, 12 mu g and 24 mu g, was shown to produce at least 12 hr of b ronchodilating effect in most patients. However, there was considerabl e individual variation in duration of effect.