DOSE-RELATED RESPONSE TO INHALED FLUTICASONE PROPIONATE IN PATIENTS WITH METHACHOLINE-INDUCED BRONCHIAL HYPERRESPONSIVENESS - A DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY

Dose-response relationships with inhaled corticosteroids in the treatm ent of asthma have been difficult to establish. A multicenter, double- blind, parallel-group study was conducted to evaluate the clinical eff icacy and safety of low doses of inhaled fluticasone propionate (FP) i n patients with mild to moderate asthma. Methacholine challenge testin g was conducted in addition to measurement of traditional efficacy var iables. After a single-blind screening period, 138 patients greater th an or equal to 12 years of age were randomly assigned to receive place bo, FP 50 mu g, or FP 100 mu g, twice daily for 8 weeks. The results o f methacholine challenge testing averaged over all visits favored FP 2 00 mu g/day over placebo and FP 100 mu g/day (p < 0.05); there were no significant differences between placebo and FP 100 mu g/day. Mean cha nges from baseline to endpoint favored each dose of FP over placebo ba sed on forced expiratory volume in 1 sec (FEV1), patient-measured peak expiratory flow (PEF), total symptom scores, and rescue bronchodilato r use (p < 0.05); there were no differences in these parameters betwee n the two doses of FP. The addition of methacholine challenge testing allowed definition of a dose-response relationship that was not appare nt with traditional efficacy variables.