Hidden surprises symptoms and conditions

I just started using Singulair a few days ago. I am 54 years old and just started coughing at night only. I would be fine during the day and then never failed, at night I started to cough keeping me awake. I was given antibiotics, narcotic cough syrups but it only helped temporarily and then I went back to coughing nights only again. So as I mentioned, I started taking Singulair a few days ago because my physician thinks I have developed allergies and Singulair is noted to help night coughs. It is helping my night coughs but I still cough a few times at night and now I cough quite a few times in the day when I never use to cough in the daytime. Wondering if Singulair is worth taking as the symptoms are becoming opposite? I hate taking drugs and don't know if I should find a safer alternative? Help, anyone? Thank you