I take 600mg of Seroquel xr every evening to keep my moods stable. At first it felt very sedating but most of the tiredness went away after my body got used to the medication.
If I don't take it I get sleep problems which triggers (hypo)manic behavior.

Maybe you'll get used to it too, but it can take few weeks.

And drinking alcoholic while on Seroquel isn't a good idea, it made me almost fall asleep at a bar once. And once I actually fell asleep after a few sips of wine.