My15 month has a bad cough with congestion would u think better to give him bromfed or zyrtec (cetirizine) ?

Neither: Better to see a doctor, meanwhile clear his nasal passages with saline, can be an upper respiratory tract infection, also keep him/her away from smokers or other sick kids/persons if you can, best of luck

Neither.: With little kids, I like to keep it simple. You'll likely get just as much benefit from a nasal saline mist than you would from any medications, and why medicate your kid when you really don't need to, right?