I was watching a thing on TV not to long ago about taking more of things. Evne with avvil etc, if you think its working, DONT take more then what is recommended. Just because 2 advil do the trick, does not mean 4 will do wounders, it can actually have the opposite effect.
My mom just found that out with Zyrtec... she was taking it for allergies and it wasn't working well so she thought she'd just take more... then her doctor told her that her liver and kidneys can't handle that. ... It's easy to think 'just take more' ... it's the american way.