Safety and tolerability of montelukast in placebo-controlled pediatric studies and their open-label extensions.

BACKGROUND Montelukast is a potent leukotriene-receptor antagonist administered once daily that provides clinical benefit in the treatment of asthma and allergic rhinitis in children and adults. Because of its wide use as a pediatric controller, there is a need for a further review of the safety and tolerability of montelukast in children. OBJECTIVE To summarize safety and tolerability data for montelukast from previously reported as well as from unpublished placebo-controlled, double-blind, pediatric studies and their active-controlled open-label extension/extended studies. METHODS These studies evaluated 2,751 pediatric patients 6 months to 14 years of age with persistent asthma, intermittent asthma associated with upper respiratory infection, or allergic rhinitis. These patients were enrolled in seven randomized, placebo-controlled, double-blind registration and post-registration studies and three active-controlled open-label extension/extended studies conducted by Merck Research Laboratories between 1995 and 2004. RESULTS Montelukast was well tolerated in all studies. Clinical and laboratory adverse experiences for patients treated with montelukast were generally mild and transient. The most frequent clinical adverse events for all treatments (placebo, montelukast, active control/usual care) in virtually all studies were upper respiratory infection, worsening asthma, pharyngitis, and fever. CONCLUSION The clinical and laboratory safety profile for montelukast was similar to that observed for placebo or active control/usual care therapies. The safety profile of montelukast did not change with long-term use.