Hello! My son started with dry cough, but rare. And his nose became st…

Hello! My son started with dry cough, but rare. And his nose became stuffed, somewhere a week ago he often coughed and because of that there were phlegm. Now just the nose is stuffed and phlegm doesn't flow out, they dry up inside. What can I do? A few months ago, a similar situation occurred, then I treated in the beginning, and after that I went to the doctor and was treated, and then it suddenly got worse and transitioned into pneumonia. Now I am afraid that it will repeat itself. I want to solve the problem with a cold at the very beginning. Zolovka recommends giving Bisoprolol suspension, has anyone given it?