Oxycodone is a short-acting opioid. Oxycodone relieves pain for about four to six hours, so it needs to be given 4 to 6 times a day to provide pain relief for the whole day. Oxycodone works by binding to specific receptors in the brain known as opioid receptors. The medicine is relatively selective for a type of opioid receptor, that is, the mu-opioid receptor.
Oxycodone is a complete agonist at the mu receptor, meaning that it does not have a ceiling effect for pain relief. The risk of side effects, like CNS and respiratory depression, rises with higher doses, and the chances of overdosage increase.