The bioavailability of oral administration of oxycodone averages within a range of 60 to 87%, with rectal administration yielding the same results; intranasal varies between individuals with a mean of 46%.After a dose of conventional (immediate-release) oral oxycodone, the onset of action is 10 to 30 minutes, and peak plasma levels of the drug are attained within roughly 30 to 60 minutes; in contrast, after a dose of OxyContin (an oral controlled-release formulation), peak plasma levels of oxycodone occur in about three hours. The duration of instant-release oxycodone is 3 to 6 hours, although this can be variable depending on the individual. Distribution
Oxycodone has a volume of distribution of 2.6L/kg, in the blood it is distributed to skeletal muscle, liver, intestinal tract, lungs, spleen, and brain. At equilibrium the unbound concentration in the brain is threefold higher than the unbound concentration in blood Conventional oral preparations start to reduce pain within 10 to 15 minutes on an empty stomach; in contrast, OxyContin starts to reduce pain within one hour. Metabolism
The metabolism of oxycodone in humans occurs in the liver mainly via the cytochrome P450 system and is extensive (about 95%) and complex, with many minor pathways and resulting metabolites. Around 10% (range 8–14%) of a dose of oxycodone is excreted essentially unchanged (unconjugated or conjugated) in the urine. The major metabolites of oxycodone are noroxycodone (70%), noroxymorphone ("relatively high concentrations"), and oxymorphone (5%).
In 2019, The New York Times ran a piece confirming that Richard Sackler, the son of Raymond Sackler, told company officials in 2008 to "measure our performance by Rxs by strength, giving higher measures to higher strengths". This was verified with documents tied to a lawsuit – which was filed by the Massachusetts attorney general, Maura Healey – claiming that Purdue Pharma and members of the Sackler family knew that high doses of OxyContin over long periods would increase the risk of serious side effects, including addiction. Despite Purdue Pharmas proposal for a US$12 billion settlement of the lawsuit, the attorneys general of 23 states, including Massachusetts, rejected the settlement offer in September 2019. Australia
The non-medical use of oxycodone existed from the early 1970s, but by 2015, 91% of a national sample of injecting drug users in Australia had reported using oxycodone, and 27% had injected it in the last six months. Canada
Opioid-related deaths in Ontario had increased by 242% from 1969 to 2014. By 2009 in Ontario there were more deaths from oxycodone overdose than from cocaine overdose. Deaths from opioid pain relievers had increased from 13.7 deaths per million residents in 1991 to 27.2 deaths per million residents in 2004. The non-medical use of oxycodone in Canada became a problem. Areas where oxycodone is most problematic are Atlantic Canada and Ontario, where its non-medical use is prevalent in rural towns, and in many smaller to medium-sized cities.