In the evening problem occurs.

I am facing a dry cough problem in the evening basically not much cough but in the mouth its like allergy are there like itching and I had a consult with cardiologist for breathing and this problem, he suggested this for allergy so he gave me montair LC and nexito plus, breathing is like normal but some I need to take from my mouth, I dont know the reason, and from 3 days inner side of mouth is itching feeling  like there is some cough stucked, I am doing gargeling two time with warm hot water, what should I do, this problem basically in the evening, What medicine should I take and there was a little bit cough but very small portion, so after suggesting I am also taking omee20 for any kind of gastiac problem, should I take any antibiotic regarding this problem, or it will go its self? The same problem has my mother also from last 2 or 3 years, she has dust allergy, any type of type antibiotic should I take? Please suggest, it is happening just evening time, sometime tension comes