I was told that the over the counter cough mixtures just don't work in kids and can be dangerous? Not sure if you can still get it but we had robitussin chesty cough with we thought helped DS when he had bronchitis. We have since found out that our kids cough's are due to asthma so ventolin helps.

I also do what Arimeh suggested, honey/warm water and vicks and sometimes a vapouriser.