A new indication for Merck's montelukast (Singulair) that allows once-daily use for the relief of symptoms of perennial allergic rhinitis (PAR) in patients 6 months of age and older has been approved by the FDA. The approval was based on data from clinical trials that showed once-daily treatment with 10 mg of montelukast significantly decreased daytime symptoms of nasal congestion, rhinorrhea, and sneezing from baseline during a 6-week period compared with placebo.

Montelukast was previously approved for the prophylaxis and chronic treatment of asthma in adults and children 1 year of age and older and for the relief of symptoms due to allergic rhinitis in adults and pediatric patients 2 years of age and older. The medication is also indicated for the prevention and chronic treatment of asthma in adults and pediatric patients 1 year of age and older.

Montelukast was generally well tolerated in clinical trials of both children and adults. The most frequently reported side effects included headache, ear infection, sore throat, and upper-respiratory infection.

Montelukast is available in tablet form for adults, chewable flavored tablets for children 2 to 14 years of age, and in oral granules for children 6 months to 5 years of age.