Seroquel has a paradoxical effect when it comes to the drowsiness side effect. It causes more drowsiness at the lower dosages (generally 100 and under) and as the dose gets larger, the drowsiness side effect actually becomes less prominent weirdly enough. It knocked me on my butt at 100mg, but at 300mg it wasn't nearly as sedating (still somewhat though). My husband takes 400mg every night and is able to get up at 4AM to go to work each day.

There is a extended release version that I've also tried. What I liked was that it gave me a few hours after I took it before I had to go to bed and I didn't find it quite as sedating in the morning. On the other hand, my husband can't take the extended release as it really sedates him (go figure).