Hi Rick,
I got this from a question that Karen Lee Richards answered:
"The oxycodone portion of percocet has a half-life of 3.2 hours for
the regular version and 4.5 hours for the extended release version.
(The half-life of a medication is the time it takes for your body to
metabolize and excrete a drug so that half of the drug is removed from
your body.) As a general rule you are considered fully clean in blood
and urine after 5 half lives. So for regular percocet, that would be 16
hrs. and 22.5 for extended release.
Keep in mind that the half of every drug varies greatly. Half-life
can also vary from patient to patient if the patient suffers from
altered kidney or liver function. For a more accurate estimate for a
specific medication, check with your pharmacist. "
Karen is a writer and a pain care advocate. You can read more about Karen here, and you can read all of her shareposts here.