For the first few days (taking 2 100mg pills each day) I felt mostly dopey (stoned) and my vision got blurry at times, slight ringing in the ears, and slight pain in my arms. None of this was extreme, but worth noting. I was prescribed this "narcotic" for a slight groin pull.
Then ... on the 5th day, I took one pill around 8 in the morning and it helped alleviate some of the pain and then I took the second earlier than I normally would (2:00) and this is where the nightmare began. After about a half hour I started getting extremely dizzy (I did have lunch) and almost felt like I was losing consciousness. I forced myself to get up and walk around the office. My chest felt constricted and I had a very difficult time breathing. This lasted for several hours and was VERY scary. I had breathing problems all the way up to laying down for bed that night and fortunately the next morning, I appeared to be OK. I'm still kinda in shock and wondering what the hell happened.
I plan on letting the doctor know, I am not allergic to anything and have taken pain medication in the past (vicodin's, etc). I assure you advil will be the only thing going in my system from this point forward. Just be careful.