Background: Despite the risk of drug-induced delirium, it is difficult to avoid the use of opioids in palliative care. However, no previous study has carefully investigated how the development of delirium varies among patients injected with different opioids for the first time.
Objectives: To reveal the difference in the incidence of delirium between different opioids.
Design: The incidence of delirium was compared among 114 patients who had started morphine, oxycodone, or fentanyl injection at Shizuoka Cancer Center between June 2012 and September 2014.
Results: The incidence of delirium was 28.9% in the morphine group (n = 38), 19.5% in the oxycodone group (n = 41), and 8.6% in the fentanyl group (n = 35). There was a significant difference between the morphine and fentanyl groups (Fisher's exact test, P = 0.04) but not between the morphine and oxycodone groups (P = 0.43) nor between the oxycodone and fentanyl groups (P = 0.21).
Conclusions: The incidence of delirium after the commencement of fentanyl injection was significantly lower, suggesting that fentanyl is a useful opioid injection drug from the perspective of delirium risk.
Keywords: delirium; fentanyl; introduction; morphine; opioid injection drugs; oxycodone.