Objective: To evaluate the therapeutic effects of H(1) blocker in combination with low dose inhaled corticosteroid on allergic asthma.
Methods: A multi-center, double blind, randomized, placebo control study was conducted in 67 patients with mild to moderate allergic asthma. Patients were randomized to receive either Loratadine 10 mg or placebo twice a day on the basis of inhaled beclomethasone dipropionate (400 microg/d for 14 days, then reduced to 200 microg/d) for 5.3 +/- 1.3 months. Symptom scores of asthma, frequencies of episode of rhinitis and common cold and doses of inhaled Salbutamol as rescue drug were recorded. Bronchial hyperresponsiveness (PD(20) FEV(1) in response to Histamine) and serum ICAM-1 and VCAM-1 were measured before and after the treatment.
Results: After treatment, there was much better improvement in symptom score (2.4 +/- 0.9 vs 3.1 +/- 0.9, P < 0.01), symptomatic days due to rhinitis (4.0 +/- 1.2 d/week vs 1.9 +/- 0.9 d/week, P < 0.001), episode of common cold symptom (0.8 +/- 0.5 time vs 1.1 +/- 0.4 time, P < 0.001), average doses of inhaled beta(2) agonist as rescue medication (2.6 +/- 0.9 puff/week vs 3.7 +/- 0.8 puff/week, P < 0.001) and bronchial responsiveness (P < 0.05) in Loratadine group as compared with the control group. However, there was no significant change in serum ICAM-1 and VCAM-1 levels after treatment in both groups (P > 0.05).
Conclusions: On the basis of low dose inhaled corticosteroid, orally administered Loratadine significantly improves the therapeutic efficacy of asthma in patients with allergic asthma and rhinitis.