This is a report on a case of delirium due to a small amount of ketamine with voriconazole. A 58 year old male was treated for multiple myeloma and hip pain due to an extramedullary tumor following the administration of oxycodone, and voriconazole was administrated for his suspected mycotic pneumonia. His pain was refractory, so we started the administration of a small dose of ketamine (4 mg/hr) for analgesia, added to oxycodone. About 30 hours later, the delirium appeared but he complained of worsening hip pain, so we added 2 mg of ketamine rapidly. Immediately after the additional administration of ketamine, his delirium became more serious. We think the reason why a small amount of ketamine induced delirium is an interaction of ketamine and voriconazole. Ketamine is metabolized to norketamine, which is thought to be more harmless than ketamine, by cytochrome P 450 (CYP) (a part of by CYP3A4) and voriconazole is an inhibitor of CYP3A4. In cases of patients treated with voriconazole, ketamine should be more carefully administrated.

Objective: This study objected to investigate temporal changes in opioid usage one week before death in terminally ill pediatric cancer patients, objecting to identify factors influencing opioid use. Methods: We retrospectively reviewed charts of pediatric cancer patients who died at the National Cancer Center Hospital between January 1, 2014, and October 31, 2022. Opioid morphine equivalent daily doses per body weight (OMEDD/kg)(mg/kg/day) were analyzed for age groups (<14 years vs. ≥14 years) and tumor types (hematologic malignancies vs. solid tumors) one week, three days, and one day before death. Results: A total of 36 patients were included in this study. Patients aged <14 years had higher OMEDD/kg compared to those aged ≥14 years at all three time points. Hematologic malignancy patients had lower OMEDD/kg compared to solid tumor patients one week and three days before death, with a trend towards equivalence on the one day before death. Conclusion: The study suggests that opioid use in terminally ill pediatric cancer patients varies according to age and tumor type, highlighting the need for individualized consideration of patient factors.