I don't feel I need Singulair on a regular basis as my asthma is controlled pretty well by Advair. When I come in contact with an allergen like dogs at someone's home I will take Singulair to get me through but will not continue to take it after. I feel that when doing this my asthma symptoms will be worse in the coming days. I am wondering if going on and coming off the drug may be the cause of this.