I picked up a box of this stuff (aka Unisom) at Savon Drugstore a thursday. Took 1 tab thursday night at 10pm, at 11pm I felt nothing so I took 11 more tab and a cap of Benedryl and drank a couple glasses of wine....fell asleep by 12:30ish.
Last night (from what I can remember

) I took 2.5 tabs of the Doxylamine/Unisom tabs and drank a few Heineken's at 11pm.....well, I just woke up AT 3:50pm Saturday afternoon!!!!! Luckily today's only appointment isn't until 6pm tonight.
This stuff is way too unpredictable to be used daily. I've read that the half-life is more than double what diphendrymine (Benedryl) is, which would account for the almost 17hour nap I just awoke from.
Stick to more reliable forms of sleeping aids.....and get'em under a doc's supervision.