Addition of Leukotriene Receptor Antagonists to Inhaled Corticosteroids Improved QOL of Patients with Bronchial Asthma Surveyed in Suburban Tokyo, Japan

Bronchial asthma is a chronic inflammatory disease that has a severe impact on health worldwide. A survey of 10,771 patients with bronchial asthma in the Tama region, Tokyo was conducted for 5 years to examine treatment and quality of life (QOL). Subjects were patients aged ≥16 years and their physicians who replied to a questionnaire sent in November from 2002 to 2006. Symptoms of bronchial asthma, visits to an emergency room, use of drugs, and severity of asthma were investigated. Asthmatic symptoms improved over the 5 years, with a reduction in the number of emergency room visits. Since inhaled corticosteroids (ICS) were used by >80% of patients in 2002, we suspected that increased use of concomitant leukotriene receptor antagonists (LTRA) and long-acting β2 agonists (LABA) might have contributed to these findings. The effects of these drugs were compared between ICS + LTRA (n = 45) and ICS + LABA (n = 54) groups of patients. There was no significant difference in the ICS dose between these groups. In the ICS + LABA group, 18.5% and 22.2% of patients visited an emergency room before and after initiation of combination therapy, respectively, with no statistically significant difference. In contrast, the rate of emergency room visits in the ICS + LTRA group decreased from 24.4% to 6.6% after addition of LTRA. These results suggest that the frequency of visits to an emergency room was decreased by complementing the anti-inflammatory effect of ICS with further treatment of inflammation, particularly with LTRA.