In addition to the drug itself being present, there may be metabolites present in your system that would affect how long it takes for it to clear, so those substances ... With a saliva test, oxycodone usage usually shows up within 15 to 30 minutes of taking a dose, and it's detectable anywhere from 1-4 days. read more
Don't know about the methadone, but, oxycodone will show for 3 to 7 days depending on how heavy the usage. You need to drink alot of fluid, excercise to a light sweat and soak in a tub of hot epsom salt water to get it out. Don't dehydrate though and take a b complex vitamin so your urine will have color. read more
It will show up longer than that. Because the half life of the medication is 4-5 hours, this means that 50% of the drug is still in your system after 4-5 hours. This means, depending on the sensitivity of the urine drug test, that the medication may be detected in the urine for up to 2-3 days after you take it. read more