Generic Singulair is an effective oral medicament prescribed for treating medical conditions, such as asthma and allergic rhinitis. It is also prescribed to prevent exercise-induced asthma (bronchospasm) in adults as well as children above six years. This medicine is ought to be used after seeking medical advice. The active drug composition of Generic Singulair is Montelukast, which inhibits a type of chemical that body releases when there is an allergic reaction. It also reduces the symptoms of seasonal (perennial) allergies in adults and children.