Oxycodone is a semisynthetic opioid analgesic that was developed in Germany in 1917 from thebaine. When you buy Oxycodone, be sure to read the Medication Guide provided by your pharmacist before you start taking Oxycodone and each time you get a refill. If you have any questions, ask your pharmacist. Oxycodone is a useful medicine for relieving severe pain when taken as prescribed, but it comes with serious risks.