What is this?

I've gone for several periods of time today without coughing... wow what a difference, and I can breathe and I even slept. Let's hope my body keeps this up. Now for my service announcement of the month. Even if you take only one type of cough pills, and even if out of the 4 variety's the 3 that you've taken in the past has you taking 2 at a time... DO NOT ASSUME it will be the same for the 4th variety. Yup I was kinda wondering why I was kinda jittery earlier today, then I checked the box to see if I had to wait 4 or 6 hours before taking my next dose... wanted to keep those nasty coughs away and the meds seemed to be working... yeah perhaps because I should have only taken one pill every 6 hours... well live and learn.