Health - Acetaminophen/Tylenol PM. Dangerous?

[RealGanjaMan]

Is it harmful to my body/mind in anyway to take 500mg - 1500mg acetaminophen nightly for a period of up to two weeks?

Latley ive been having some mild insomnia, and ive been using Tylonel P.M. to induce a sleep. I usually take the reccomended dose (1000mg, or 2 Pills) but sometimes when the insomnia is worse I will take 1 or 2 more pills (1500mg - 2000mg). Now I'm guessing this isnt too dangerous/harmful, because that is hardly even over the reccomended dose. The only thing I'm worried about it sometimes I take it nightly for up to two weeks (very rare, usually only about 5-6 days max) and I'm worried that this could be harmful to my liver/etc?

If anyone doesn't know what tylenol P.M. is,
Its an OTC sleep aid with:
Diphenhydramine - 25mg
Acetaminophen - 500mg

So what do you think?
-RGM