Dextromethorphan
"I went to my pharmacy and I asked the pharmacist what can she recommend for a dry cough she said its Delsym. I tell you you will be drowsy....so I didn't mind at all because its a good thing for me I can sleep.  When I took it I was waiting to see  if it was effective  - to my surprise I keep coughing the whole night as if I didn't take any medications....so if a cough product doesn't work for an adult - you shouldn't recommend it.....waste of money!"