Montelukast is only partially effective in inhibiting aspirin responses in aspirin-sensitive

Background: Leukotrienes have been implicated as major mediators of ASAinduced respiratory reactions. In several prior studies, pretreatment of ASA-sensitive respiratory disease (ASRD) patients with leukotriene modifiers have sometimes allowed subjects to tolerate previously established provoking doses of oral ASA or inhalation ASA-lysine, without respiratory reactions. Objective: The purpose of this study was to examine whether ASA-provoked respiratory reactions would be blocked or attenuated by pretreatment with a cystLT1 receptor antagonist, montelukast, particularly if ASA doses were increased above their threshold doses. Methods: Baseline ASA oral challenges were performed. Eight to 12 days later, following pretreatment with montelukast 10 mg daily, threshold and then escalating doses of ASA were used during repeat oral ASA challenges. The differences in responses between baseline and montelukast protected ASA oral challenges were then compared. Results: Nine of 10 patients, despite pretreatment with montelukast, experienced at least naso-ocular reactions during their second oral ASA challenges. In four of nine patients, asthmatic reactions also occurred. In comparing baseline and montelukast protected ASA challenges, there were no statistically significant differences in their responses. Conclusions: Pretreatment with montelukast allowed only one patient to proceed through all challenge doses of ASA without any reactions. The remaining nine patients enjoyed only partial protection from respiratory reactions. Montelukast pretreatment was generally not effective in altering upper airway reactions and only partly effective in altering lower airway reactions. Ann Allergy Asthma Immunol 2000;85:477–482.