It's scary to do that. A few years ago I was on pain pills after surgery and woke up and instead of my AM meds I took my PM meds. Which included 1200 mg of Seroquel, so I took 2400 mg in 12 hours along with my other meds which were at lower doses (I did also take 4 mg of klonopin at once too but that's not as bad as the Seroquel). I called my pdoc's office and had to talk to a pdoc I'd never met and promise it wasn't a (pathetic) attempt at an OD and instead was just stupid, all the while getting more and more sleepy (I think it took 15-30 minutes to be sound asleep).

I slept for about 36 hours off and on, mostly on, and remember nothing of those 2 days.

Really scary.