Hi hurricaneroll. It is very common for people who just start Seroquel to experience notable sedation. For many (it was in my case), it takes a little while to get used to the medication, but after a while, I think most people adjust to it and then the excess sedation wears off. It can take a little patience, though.

If the 25 mg X 3 during the daytime seems to knock you out too much, you might want to call your psychiatrist and tell her/him that. Perhaps they may allow you to reduce the daytime dose(s) a bit? I would consult with them, though, because they have a plan for knocking out your hypomania. But if you can't function, they may consider an adjustment.

I have taken small and large doses of regular Seroquel AND extended release Seroquel throughout my bipolar treatment. Sometimes smaller doses can be more sedating than larger doses. I've read (see Quetiapine - Wikipedia) that low doses act like an antihistamine. With that in mind, people shouldn't think that possible future high doses (like 400 to 800 mg) will knock them out significantly more than say, 150 mg.

I found that the regular release Seroquel and extended release were both helpful for me. I still take extended release (650 mg) and occasionally low dose regular as an "as needed". They may affect some people slightly different than others. In my case, there was also an adjustment to the extended release. I'd find myself very drowsy well into the morning. Again, time to adjust helped. Also, I had to find the best time to take the extended release to avoid excess drowsiness. For me, taking it at 7 pm is best. I just took mine 15 mins ago, and it's 7:13 pm. Also, it's important for me to go to bed at a reasonable time. No more "night owl" for me. It is best if I go to sleep by 11 pm, ideally. I can do a midnight occasionally, but only because I'm more than used to my Seroquel XR after 8 years. Frankly, when I take 50 mg of the regular Seroquel in the morning (when hypomanic), it no longer tires me out at all. It maybe curbs the flames of my hypomania, but that's it. That's "adjustment".

As a final note, I am more a fan of the extended release than the regular. For me, the extended release is mostly weight neutral. Especially since I mastered the when to take it, and when to go to bed. And adjustment. The regular release's timing seems to trigger bigger appetite in me than the extended release. What I call "the higher and quicker spike" of the regular release is part of that, for me.