Change the Dose Frequency of Controlled-Release Oxycodone to Refractory Pain

Many patients with cancer experience moderate to severe pain that requires treatment with strong opioids, of which oxycodone and morphine are examples, they are widely applied in clinical treatment because of sustained-released formulation can reduce dosing frequency. Goal of pain management is get adequate analgesia and minimize the adverse event at the same time, but in fact there are about 10%-30% patients can't get adequate analgesia because of intolerable adverse event. The common adverse event of Controlled-Release Oxycodone(CR Oxycodone ) are nausea (29.9%)、constipation （25.4%）、dizziness（22.4%） and vomit（11.9%），about 32.8% patients treatment was discontinued because of these adverse event. The peak concentration of opioid is related to adverse event, while the valley concentration is correlated to the analgesic effect. Therefore, if we keep the daily dose while increase the dose frequency so that reduce the single dose, it's will help to avoid intolerable adverse event caused by excessive opioid peak concentration and keep the opioid analgesia at the same time. It's a reasonable way to solve the side effects of opioid. In order to explore the effect of change the dosing frequency of CR Oxycodone to treat refractory pain, pre-experiment have done by several clinical centrals in Fujian province. Preliminary results show that for the patients who can't accept the current opioid dose because of intolerable side effect, changing the dosing frequency is a safe and effect way.