RESUMEN
PURPOSE: Oral naloxone is combined with oxycodone to alleviate or prevent opioid-induced constipation in cancer pain patients. However, there is still concern that oral naloxone may precipitate opioid withdrawal symptoms in patients on opioids. We retrospectively investigated clinical characteristics of cancer patients who experienced opioid withdrawal symptoms. METHODS: We reviewed medical records of all patients who were prescribed with oral oxycodone/naloxone at a tertiary cancer center from January 1, 2012 through December 31, 2016. Eligible patients were screened based on demographics, opioid and naloxone dosages, clinical manifestation and pain intensity. RESULTS: Among a total of 1,641 patients, 10 patients were selected. Seven patients were male, and the average age was 68.1 years. The median dose of naloxone that induced withdrawal symptoms was 20 mg. Most common withdrawal symptom was shivering (seven patients) followed by cold sweating (five), and muscle twitching (five). Other symptoms included restlessness, fever, dizziness, and yawning. Pain was exacerbated from the median intensity of numeric rating scale (NRS) 3 to NRS 6. CONCLUSION: Opioid withdrawal symptoms may occur when switching to oral oxycodone/naloxone for cancer patients who have been treated with other strong opioids. A prospective, multicenter study on this issue should be conducted in future.