BACKGROUND:bera2-agonists are one of the most frequently prescribed drugs for bronchial asthma, due to their rapidity in onset and potent bronchodilatory effect. A highly selective new bera2-agonist, salmeterol is known to have duration of action more than 12 hours. Furthermore there are some reports supporting their effects on the allergic inflammatory processes.
METHODS:We assessed the clinical efficacy and safety of salmeterol in 24 patients with moderate asthma. Our study protocol was composed of a run-in period of 2 weeks and a treatment period of 10 weeks. At the end of the run-in period, they were randomized to one of two treatment groups: a mono-therapy group (13 patients; salmeterol, 50ug, bid) and a combined therapy group (11 patients; salmeterol, 50/micro gram, bid and budesonide, 400/micro gram, bid). All patients were not allowed to use other drugs except supplemental salbutamol. Follow-up parameters are symptom scores, PEF, supplemental salbutamol use, FEV1, methacholine reactivity, and various clinical and laboratory profiles of side effects. Symptom scores and PEF were recorded in daily cards before inhalation of the study drugs. FEV, and methacholine PC20 were checked after all of the study drugs were withheld for at least 24 hours. Statistical analysis was available in 18 patients (9 patients in each groups) who had finished the whole study periods. Each of the parameters in the 5th or 10th week were compared with those of the run-in
RESULTS: 1. Differences between treatment groups were not statistically significant in their age, PEF, supplemental salbutamol use, FEV, and methacholine reactivity (PC20) during the run - in period. 2. Day and night-time symptom scores decreased significantly in both groups after treatment (in the 5th and 10th week (p<0.05, respectively). 3. Morning PEF levels increased significantly in both groups (in the 5th and 10th week; PC 0.05, respectively), but evening PEF levels only in the combined therapy group (P<0.05, respectively). 4. Additional use of salbutamol decreased significantly in the combined therapy group (in the 5th and 10th week;P<0.05, respectively), but only in the 10th week in the mono - therapy group(P < 0.05 ). 5. FEV1 levels increased significantly in the combined therapy group after treatment (in the 5th and 10th week; P<0.05, respectiviely), but not in the toorio-therapy group. 6. After treatment period of 10 weeks, PC20 for methacholine increased 1.6 fold logarithmically in the mono-therapy group (P>0.05), and 2.8 fold in the combined therapy group (P