Quetiapine
"It's a wonderful knock out punch if everything else has failed, or if you've taken something like Ambien and it stops working. For me Ambien was great until it stopped working, I then tried Trazodone but that didn't help much. Seroquel is an antipsychotic but at small doses (25-50mg) it only hits histamine receptors so its like a large dose of Benadryl- but much better then Benadryl. Only downside is that it is a little hard to get out of bed the next day but you will sleep like a bear so it's worth it. Takes about an hour to an hour and a half to kick in and 25 mg does the trick for me. Also, there is no weight gain at small doses so that's nice too."