Have you given your 2 year old this medicine?

My 2 year old little boy developed a congestive cough on Thursday, so Friday I took him to his pediatrician and she prescribed him a cough syrup called BROVEX PEB DM LIQUID, I was wondering has anybody else gave this medicine to they're child and if so how does it work and how quickly will I see him getting better. Note: he now has a runny nose, is this because of the medicince and that its working and getting rid of all his phlem.