Cold medicines

This is a little scary. When my girls have a cold, all I want is for them to feel better. I have called their pediatrician before, asking what to give them, and I've been told I can give them a teaspoon of "this", or a half teaspoon of "that", even though "this" and "that" may be medicines that are labeled for children six years and older. Now it sounds like that's not such a good idea after all. I will definitely be watching for more information on this subject.