How long does Percocet 7.5/325 or Kadian (morphine) stay in your blood stream for?

The chronic pain site says: "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."

Other sites say, depending on how long a person is using, up to 3 days - someone who failed a drug test after 24 hours posted that.

Morphine - blood for "about 8 hours;" urine for 72 hours.

How long can oxycodone be detected in your urine for a drug screening

For a drug test 3 to 5 days