Montelukast can be given in combination with other asthma medications, and it does not interact with warfarin or theophylline. It or if you have any other allergies. Singulair is a prescription tablet, approved to help control asthma in adults and to relieve symptoms of unrelenting allergies. Montelukast can be given in combination with other asthma medications, and it does not interact with warfarin or theophylline. Use of this medication is not recommended in children less than 15 years old.