Background: There are few studies that have examined the long-term efficacy and safety of pranlukast, a leukotriene receptor antagonist, in asthmatic patients.
Methods: Sixty-three asthmatic patients were entered in this 4-year study [group 1, mild or moderate (N = 22); group 2, severe without using oral prednisolone (N = 22); group 3, severe with using oral prednisolone (N = 19)]. Pranlukast was administered at 225 mg twice daily to 14 subjects in group 1 (group 1p), 14 in group 2 (group 2p), and 11 in group 3 (group 3p), chosen for pranlukast additional therapy at random. Another group of 24 asthmatic patients was assigned to conventional therapy group (groups 1c, 2c, and 3c). Efficacy was determined by improvement in symptom score, peak expiratory flow rate (PEFR) percentage predicted, reduced daily variability of PEFR (percentage), and reduced frequency of use of rescue beta2-agonist (times per week).
Results: In groups 1p and 2p, PEFR percentage predicted began to improve from 2 weeks after commencement of treatment. The symptom score, daily variability of PEFR, and use of rescue beta2-agonist diminished significantly. In group 3p, pranlukast was ineffective in improving PEFR percentage predicted. All but two patients continued to receive pranlukast and no adverse effects were noted, at least during the 16-week therapy. Further, 22 patients continued to receive pranlukast for 4 years, and none experienced any adverse effects.
Conclusions: We showed in this study that long-term treatment with pranlukast is effective for asthmatic patients without any adverse effects.