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%).
Bednars aphthae is a type of oral ulceration (mouth ulcers) which occurs in infants. The lesions are located on the palate and are caused by trauma. No treatment is required since the lesions heal within a few days.The condition was first described in 1850, by the Austrian physician Alois Bednar (1816-1888). References


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