My pedi is ok with us giving a small dose of adult cough syrup...you might want to check with your pedi. But I've found that honey works just as well--I give the Little Noses Honey Elixir, just because it's easier to dispense to them than regular honey.
I think most have been taken off the market or at least have new labeling that states not for children under 2. The american college of pediatrics changed their recommendation to not under 7yo recently. That being said, my pedi said if we really felt we needed to use it, try Delsym. Luckily, we've never had to use cough syrup because we've always had really good luck with a teaspoon of honey, even for really bad coughs.
Hyland's makes a "Cold & Cough" and "Cough" for ages 2-6. It's sold at Wal-Mart. It's the youngest I know of. I give that to my 3 yo. For my 14 mo I only give an Rx that the pedi gave us.
Re: cough meds for toddlers?
warm salt water
honey on a spoon