Background: Elderly patients are more likely to be affected by the acute and chronic toxicities of opioids, but an association between age and long term opioid consumption has not been established clearly in patients with advanced cancer.
Methods: The computerized records of 197 cancer patients admitted to a palliative care unit in Edmonton, Alberta, Canada were examined. The authors examined: demographics (age, gender, and location of primary tumor), pain characteristics (presence of neuropathic pain and incidental pain), mean daily pain intensity (MDPI), and daily opioid consumption measured as (parenteral) morphine equivalent daily dose (MEDD). MDPI and MEDD were assessed on Days 2 and 7 after admission, on the day of maximum opioid consumption, and on the day of maximum pain intensity during admission. Average values for MDPI and MEDD were calculated between Days 2 and 7.
Results: When age was treated as a categoric variable (< 65 years, 65-74 years, and 75+ years), statistically significant differences in MEDD were observed for age for all estimates except those for Day 7, with older patients requiring a lower equianalgesic dose. No major differences were observed for pain intensity and for the presence of incidental or neuropathic pain across the different age groups. In the multivariate analysis, the reduction in MEDD ranged between 27-71 mg when patients age > or = 75 years were compared with younger adults. A MEDD increase that ranged between 82-137 mg was associated with the presence of neuropathic pain.
Conclusions: The current study suggests that elderly cancer patients may experience a similar level of pain intensity but require a lower amount of opioid analgesia than younger adults. However, because elderly patients are more likely to be affected by the acute and chronic toxicities of opioids, opioids should be initially administered at a lower dose and titrated cautiously in these patients.