i have personally found that when i take OXY, just say right now i took 20 mgs of OXY, then 45 minutes later, i have that little head buzz goin, then i decide to take another 20 mgs, i usually NEVER feel that much of an extra buzz ontop of what i got from the initial 20 mgs..im not sure why, although there is some reasoning behind this..it does seem thought that if i wait 2-3 hours between doses, i feel the effects MUCH BETER..
so IMO, when taking OXY, decide on what dose will be good for you, then take it all AT ONCE!!then wait 2-3 hours and take the next one..