[The effect of salmeterol on specific and non-specific bronchial response in allergic asthma patients]

The effect of a single dose of salmeterol, long-term, regular treatment with salmeterol and a termination of the therapy on specific and non-specific bronchial reactivity were evaluated. The effect of the therapy on serum ECP level was studied too. The studies were carried out in a group of 16 mild asthmatics sensitive to mite allergens. Both types of bronchial challenges were performed according to Ryan's method. Blood samples to evaluate the ECP level were collected before treatment and on the day before the last day of the study. The single dose of 50 micrograms of salmeterol taken 3 hours before bronchial challenge significantly decreased the bronchial response to histamine (the average PC20FEV1 value increased about a four fold after salmeterol) and to the Dpt allergen (PD20FEV1 increased 3.5 fold). No effect of salmeterol on LAR was observed. Bronchial reactivity to histamine was significantly lower in the period of the therapy and did not differ from the baseline 12 hours after stopping the treatment. PD20FEV1 Dpt during the therapy was about 3 fold higher than the baseline but 36 hours after stopping the treatment did not differ from the baseline. Although the patients had inhaled a 3-fold higher dose of allergen to induce EAR, the frequency of LAR did not change. No anti-inflammatory effect of salmeterol was observed.