The half-life of oxycodone is two to six hours and can be detected in the urine for two to four days after ingestion.
Because oxycodone is metabolized to oxymorphone, both oxycodone and oxymorphone can be detected in patients taking oxycodone.
Since the cross-reactivity of oxycodone and its metabolites in opiate immunoassays is very low, laboratories must employ the use of a separate oxycodone/oxymorphone screen in addition to the 'regular' opiate screen.
