Pretty much everything over the counter is ok, except for aspirin. You should get an ok from your doctor first of course.
However, I have found most OCT remedies to be mostly ineffective in treating colds and sore throats, versus lemon and buckwheat honey that you can obtain at grocery stores. It's natural and more healthy for the baby. Research has found that lemon and honey are actually just as effective if not more effective than OTC remedies for children.
So why not give that a try and put any possible risk to the side?