[Effect of vaginal administration of controlled-release oxycodone on cancer pain]

Controlled-release oxycodone is an orally administered strong opioid analgesic for moderate to severe cancer pain. Sometimes, its oral administration has to be stopped because of continuous nausea, vomiting, conscious disturbance, or inability to swallow. This study was to investigate analgesic effect of vaginal administration of controlled-release oxycodone on cancer pain and observe adverse events to provide a new choice for female patients who can not tolerate the adverse events caused by oral administration.

Controlled-release oxycodone tablets were vaginally administered to 36 female patients with moderate to severe cancer pain. The initial dose was 10 mg every 12 h to patients who had never taken opioid analgesics; former dose continued to patients switching to vaginal route from oral route.

Among the 36 patients, six had complete relief of cancer pain, 20 had significant relief, four had moderate relief, and four had slight relief, two had no relief. The relief rate of cancer pain was 83.3%. The mean time for onset of analgesic effect was 49 min; the mean duration of analgesic effect was 13.8 h. Main adverse event was vaginal burning sensation in nine (25.0%) patients. No patient discontinued vaginal administration because of adverse events.

The vaginal administration of controlled-release oxycodone is a safe,effective and simple means of managing cancer pain in female patients who can not tolerate the adverse events caused by oral administration.