In all cases you can use food to adjust how well Seroquel works for you.  Take it with food to get a little boost.

Seroquel's Dosage for bipolar mania: AstraZeneca recommends starting at 100mg a day in two 50mg doses and increasing to 400mg day by day four. Further dosage adjustments up to 800mg a day by day six should be done in increments of no greater than 200mg a day.  Yow.

OK, the 100mg a day is OK, but unless you're seriously flipped, going up by 100mg a day each day is a bit fast in my book.  And if you're taking other meds, 25-50mg a day might be good enough. 

Sure, if you're in a hospital or otherwise getting some kind of 24/7 care and barely know where you are, then the aggressive titration in the PI sheet is warranted.  But if you got yourself to the doctor,  you know what day of the week it is and you haven't maxed out your credit cards, I suggest giving the starting dosage of 25-100mg a chance to work.  Especially if you're taking other meds to treat the bipolar disorder.  Now from all the research I've been looking at the typical effective dosage to treat bipolar disorder is in the 300-600mg a day range, and that's with or without other meds.  So while it's not likely that 25-100mg is going to be a long-term effective dosage for most people, other than helping you sleep, which is often quite helpful in of itself, the lower dosages can be helpful in the short term.  And starting any med at a lower dosage just lets you get used to them, thus preventing side effects that suck too much.

I'm really not a big fan of antipsychotics as monotherapy for bipolar disorder.  Unless you're unable to tolerate any anticonvulsant, I think Seroquel (quetiapine fumarate) and the other atypicals are best reserved as crisis meds and as add-ons.  While there are people for whom Seroquel (quetiapine fumarate) will be the medication to treat their bipolar disorder in the long run.  But the main reason these meds are getting a big push to treat bipolar disorder right now is just to pad the pharmaceutical companies' bottom lines.  Lithium and anticonvulsants are less expensive and, except for lithium's issues with hypothyrodism, have fewer long-term issues.

Seroquel's Dosage for schizophrenia.  Oddly enough AstraZeneca is OK starting you out at 50mg a day, divided into two doses.  While they still want to ramp you up to 300-400mg a day by day four, at least they're willing to start you a bit lower.  Again, unless you're completely flipped out, I'm all for slowing that down a bit.  The PI sheet and my research both agree that the magic dosage is usually in the 300-500mg a day range, split into two or three doses a day.  Taking it two or three times a day - whichever works better for you, that's just going to be a process of experimentation.  One study on the matter  couldn't find much difference, so whatever is going to work better for you is the way to go.

Seroquel's Dosage for insomnia and other sleep disorders - 25-50mg a night should be enough to start.  Sometimes more than enough, and 12.5mg is more than enough for some people.  Going over 100mg a night is often counter-productive, but mileage will certainly vary.  Like many sleep promoting drugs, you don't need to take it every night if you don't have trouble sleeping every night.

Seroquel's Dosage for Panic/Anxiety - 25-100mg a night should do it, but this is something you and your doctor will really have to work out.  There just isn't enough published literature on its use for panic and anxiety, unfortunately.  You may also have to take it during the day, in which case you'd probably want to start at 12.5-25mg because of the sedating effects.

How Long Seroquel Takes to Work: It's the slowest of all the atypicals, despite the short half-life and steady state.  Seroquel can take one week to start working for schizophrenia.  Compared with a shot of intramuscular Zyprexa, which can work in two to twenty-four hours.   I've read reports from people with bipolar and/or anxiety who write a similar timeframe - a week or two.

Now if you're taking it just to go to sleep, 25mg should knock you out the first night you take it.  You'll fell like crap the next morning, but it's just that first morning that's the worst for the majority of people.

How to Stop Taking Seroquel: Your doctor should be recommending that you reduce your dosage by 25-50mg a day every other day if you need to discontinue it.  For more information, please see the page on how to safely stop taking these crazy meds.   You can stop cold turkey if it's an emergency, but I wouldn't recommend doing that without a doctor's supervision.  The major problem with stopping antipsychotics is a sudden return of your symptoms.

So if you're at 300mg a day you take 250mg on Monday and Tuesday, 200mg a day Wednesday and Thursday, 150mg a day Friday and Saturday and so forth until you're done.