Original articles Comparison of the eVects of intravenous and oral montelukast on airway function: a double blind, placebo controlled, three period, crossover study in asthmatic patients

Background—Montelukast, a leukotriene receptor antagonist, improves parameters of asthma control including forced expiratory volume in one second (FEV1) when given orally to patients aged six years or older. This study was undertaken to compare the eVect on FEV1 of intravenous and oral montelukast and placebo during the 24 hour period following administration. Methods—Fifty one asthmatic patients (FEV1 40–80% predicted and >15% improvement after inhaled â agonist) were enrolled in a double blind, single dose, three period, crossover study to receive intravenous montelukast (7 mg), oral montelukast (10 mg), or placebo in a randomised fashion. The primary end point was area under the curve (AUC)0–24 h of the percentage change from baseline in FEV1. Additional end points were maximum percentage change in FEV1 and percentage change at diVerent time points. Results—Compared with placebo, intravenous and oral montelukast significantly increased the AUC0–24 h (means of 20.70%, 15.72%, and 7.75% for intravenous, oral and placebo, respectively; no statistical diVerence between intravenous and oral). The diVerence in least square means from placebo for intravenous montelukast was 13.27% (95% CI 7.07 to 19.46), p<0.001 and for oral montelukast was 7.44% (95% CI 1.20 to 13.68), p = 0.020. The maximum percentage change in FEV1 was not significantly diVerent for intravenous and oral montelukast (diVerence in least square means 6.78% (95% CI –0.59 to 14.15), p = 0.071). The mean percentage change in FEV1 for intravenous montelukast was greater than for oral montelukast within the first hour (15.02% vs 4.67% at 15 min, p<0.001; 18.43% vs 12.90% at one hour, p<0.001 for intravenous and oral montelukast, respectively (placebo 3.05% at 15 minutes, 7.33% at one hour). Intravenous and oral montelukast were similar to placebo in the frequency of adverse events. Conclusions—The onset of action for intravenous montelukast was faster than for oral montelukast and the improvement in airway function lasted over the 24 hour observation period for both treatments. Although not well understood, there was a trend toward a greater improvement in FEV1 with intravenous than with oral montelukast. These findings suggest that leukotriene receptor antagonists should be investigated as a treatment for acute severe asthma. (Thorax 2000;55:260–265)