I had never heard of Robotussin/Robitussin before but it seems it was referenced as early as 1967 by Moby Grape. So the active ingredient of this beverage is codeine?
I do remember trying cough medicine at school. Benyllin I think it was called but it didn't do much for me apart from a little fuzziness.
What is Gbl, Loulou Reed?
The active ingredient is Dextromethorphan. DXM.