Oxycodone 40 mg is a potent ,extended-release. It is used to relieve pain severe enough to require opioid treatment. It belongs to a group of doctors. It acts on the central nervous system to relieve pain. This drug is used judiciously for pain management. Its dangerous side effects include extreme sleepiness,confusion etc. Its side effects are like; Constipation,vomiting,stomach pain,extreme tiredness etc. If you experience any symptoms get emergency medical treatment;slowed breathing, long pauses between breath or shortness of breath.