Wow, I just logged in to ask this exact question! I only recently realized what I've felt many times and thought was a med. side effect are panic attacks or "limited symptom" panic attacks. I think mine would be considered "minor" but they still suck, especially when I'm driving.

Suddenly and for no reason, reality shrinks in on me along with a strong, very unpleasant buzzy, tingly feeling all over my body and mind. My vision narrows (fuzzy around the edges) and I feel very warm-hot and start sweating. I think I'm going to pass out. Very light-headed. Feel detached from my body and when I'm driving I think I can't feel the steering wheel - don't worry, I still have the car under control and can see everything fine, but of course I pull over. It has always been a very random for me - I have no idea what triggers it and there's never any fear - other than passing out.

Want to see how I kind of feel when it happens? Look at this YouTube video I came across today of a young lady who recorded her panic attack while on the computer with her webcam. WARNING: You know you might trigger your own attack if you watch something like this, right? But like the girl on the video says, she's having a "mild" attack.