Assessment of switching ratio in 8 cases treated by Oxycodon switched from oral to injection

ABSTRACT

Extended－release Oxycodone tablet has been available for cancer pain treatment since 2003 in Japan. After pure oxycodone injection became available in 2012, we have tried to switch from oral to injection when oral intake becomes difficult because of bowel obstruction, nausea or drowsiness due to progression of the disease. There is no evidence regarding the ratio of switching from oral to injection at present in Japan. We always pay attention to avoid patients drowsiness because of an overdose of opioid, because there is not enough time left for cancer patients in the terminal stage, and drowsiness takes away from the patient’s good QOL. We switched Oxycodone from oral to injection in 8 cases from June to December in 2012. At first, we assess if the patient is well controlled by oral oxycodone or not. If the patient is not relieved from the pain enough, we switch oxycodone from oral to continuous subcutaneous injection with a dose of around 75％ at first. After that we titrate the dose little by little up to an appropriate level. We were able to evaluate 5 patients out of 8 because there were 3 patients with consciousness disorder. As a result, we were able to decrease dosage to 46.4％ on average.