[CaminoDeOro]

So seroquel has a very short half-life and indeed there is an XR version. I understand it's usually prescribed at bedtime due to the drowsiness, but it makes me wonder about how fast it might lose effectiveness over the following day due to that short half life. Especially when it's often dosed once a day.

Does anybody know of any semi "official" writing/opinions on this topic? Obviously a medication's therapeutic lifespan and half-life are not always one and the same. It would seem to me that a bedtime dose of seroquel should be working noticeably less well by evening of the following day, but in my case I'm taking it as a mood stabilizer rather than (for example) an antipsychotic, so I imagine it's harder for somebody like me to tell.

I've been searching around for info on this but so far all I've come up with is unbacked speculation on forums

[childofchaos831]

https://www.ncbi.nlm.nih.gov/pubmed/18312041

Definitely a lot of science language here, but the conclusion on the abstract page may help. This is The closest I could find to an answer. It's a science journal/publication, and this is the article of a study done on the difference between immediate release and extended release.

[WildcatVet]

Just to confuse you even more, while the quetiapine half life is 7 hours it's active metabolite, norquetiapine, has a half life of 9 ~ 12 hours.

[CaminoDeOro]

ohhhhh there's an active metabolite. Okay, it makes a bit more sense now.

Thanks for the journal article link, that is precisely the type of source I'm looking for. So tl;dr it seems that if your metabolism is normal and you're on 300+mg/day of immediate release, the curve is pretty smooth.

I'm on 150mg/day but I'm a CYP2D6 poor metabolizer... so I probably could just take it all at bedtime, its half-life is going to be longer for me anyway.

Thanks!!

[childofchaos831]

I'm glad that is what you were looking for! Searching for it took me back to my college days... I had majored in psychology at a 4 yr uni until I ran out of financial aid, but I finally finished a 2 yr degree in Social Work. At the 4 yr school, finding articles like that and reading/understanding them was almost a daily thing. The key word is "keywords" heheh!

[CaminoDeOro]

I just wish we could count on all or most prescribers to know stuff in this much detail, but then again I'm researching only the subset of stuff relevant to my particular issues and it's still too much to keep up with.

[WildcatVet]

Researching is good...new studies come out every day. Progress is being made...