高用量オピオイド鎮痛薬長期投与から子宮体がん根治術により完全離脱できた1症例

抄録

We report a case of pharmacist intervention where a patient with uncontrolled pain after long-term use of high-dose opioid analgesics achieved complete opioid withdrawal post-radical cancer surgery. The patient was a woman in her sixties. At the time of being diagnosed with endometrial cancer in X, she refused aggressive treatment and was subsequently given sustained-release Oxycodone for pain control. In X + 6 years, she experienced uncontrollable pain and underwent radiation therapy for pain relief. Her sustained-release Oxycodone dose was reduced post-therapy. In X + 9 years, her pain again became uncontrollable. She underwent a total hysterectomy for pain relief, and her sustained-release Oxycodone dosage was tapered. She achieved complete withdrawal on postoperative day 316. At the following two points during the course of observation, pharmacists evaluated problems pharmaceutically and intervened in the dose reduction process.

1. When the sustained-release Oxycodone dosage was reduced from 80 mg/day to 60 mg/day, the number of rescue doses was increased, resulting in a non-reduction of total opioid dosage and uncontrolled withdrawal symptoms.

2. Upon further reduction of Oxycodone from 30 mg/day, there was no appropriate method for equally dividing the dosage taken three times daily. In this case, the main cause of pain was considered to be the cancer itself and complete pain relief by radical surgery may have led to total opioid withdrawal. The pharmacist intervention was considered useful in re-evaluating the drug reduction process and controlling withdrawal symptoms.