The morphine myths suggest that strong opioids induce physical tolerance although solid scientific support for these myths is not present. Many physicians still postpone the use of morphine in palliative cancer patients "to reserve this effective pain treatment for the difficult terminal phase of life". More research data are necessary to clarify this problem.
Material and methods: The consumption of transdermal fentanyl is calculated during at least 3 and at most 24 months in 171 advanced long surviving (>13 weeks) oncological patients that are no longer treatable with anti-tumour therapies. All patients were up-titrated with oral morphine to a pain score ofB/30 on a visual analogue pain score (0-100), than the morphine dose was replaced by an equivalent dose transdermal fentanyl.
Results: The mean daily fentanyl dose increases during the first 4 months from about 50 mg./h. to 150 mg./h. There was between month 4 and 24 no further increase of the mean daily fentanyl consumption while the VAS pain score was continuouslyB/30. There was no significant difference between patients 60 years.
Conclusion: This study offers scientific evidence that opioid tolerance seems to be limited both in quantity (increase of the daily equivalent morphine dose to about 500-600 mg morphine equivalent dose per day) and in time (3-4 months). These data do no longer justify that effective pain treatment is postponed for the last phase of life in advanced cancer patients. It's the duty of every patient, family and caregiver to treat cancer pain effectively, independently from life expectancy.