PONTE VEDRA BEACH, FloridaCancer patients with bone
metastases who received around-the-clock (ATC) analgesics took substantially more
medication but did not have better pain relief than patients on as-needed (pro
re nata, PRN) dosing regimens in a study reported by Christine Miaskowski, RN,
Dr. Miaskowski, chair, Department of Physiological Nursing,
University of California, San Francisco, presented the results at the Oncology
Nursing Society’s Sixth National Conference on Cancer Nursing Research
The researchers tracked the two groups for 5 weeks and found no
differences in pain intensity measures. Yet patients in the ATC group had been
prescribed an opioid analgesic dose five times higher on average than the dose
given to the PRN group. The dose actually taken by the ATC patients was 12
times higher, she reported.
Describing ATC dosing of analgesics as a fundamental tenet of
managing cancer-related pain, Dr. Miaskowski said that the surprising findings
have significant clinical implications that merit further investigation.
"The variances were really big," she told ONI in a
postconference interview. "We know very little about how providers make
decisions about how to give analgesics to patients. We need to look at how
patients take drugs, too. How do they report pain? We know virtually nothing
about the decision-making process."
The researchers evaluated 74 ATC patients and 62 PRN patients,
who were drawn from seven different cancer centers in Northern California.
Patients had to have an ATC opioid prescription and take 80% or more of the ATC
dose for 5 weeks to be classified in the ATC group.
The patients in the ATC group had lower Karnofsky Performance
Scale scores than those in the PRN group, but otherwise showed no differences
in demographic or disease characteristics.
The study is one of the longest to track cancer pain, according
to Dr. Miaskowski. Four separate analyses found no divergence in pain
intensity measures such as average, least, or worst pain scores, and number of
hours a day in pain.
The researchers offered a number of potential explanations for
future investigation, including the possibility that the current pain
medication regimen is not effective for bone metastasis. A new kind of drug
might be needed, she said. Also questioned was whether pain intensity scores
are appropriate for analyzing analgesic regimens and whether analgesics are
being titrated in response to the level of pain being reported by the patient.
Clinicians need to think more about assessing pain, titrating
doses, and anticipating side effects, she suggested, calling side effects
"the major reason patients don’t take their analgesics."