HOUSTON—There are different kinds of cancer pain and not all of them require opioids—for example, pain management might at various times mean management of suffering, rehabilitation, function counseling, or other maneuvers.
“Pain is always a multidimensional construct; it is never just electrical activity going through the dorsal horn,” said Eduardo Bruera, MD, Professor and Chair of the Department of Palliative Care and Rehabilitation Medicine at the University of Texas MD Anderson Cancer Center, speaking here in an introductory lecture at the 18th Annual Interdisciplinary Conference on Supportive Care, Hospice, and Palliative Medicine, sponsored by MD Anderson. “We need to be cautious with the interpretation that the word pain always means more opioid.”
He said attempting to measure pain on a scale of intensity as a nociceptive equivalent is an error: “We cannot measure the production of pain. If we could, we would have our problem solved; we could titrate our opioid the same way a diabetic titrates insulin. A number such as 8 out of 10 does not tell us where the pain comes from, as there is a wide variation in production of pain, in perception of pain, and in the way we express the pain.”
If, however, it were possible to determine the origin of pain for a patient who scores pain as 8/10, and 85 percent of that was from nociception, that patient's pain will respond to opioids, Bruera said.
But a patient with only 30 percent of the pain due to nociception and the rest due to somatization, tolerance, incidental pain, or chemical coping, will not. “Do not react reflexively and ‘throw the drugstore’ at the patient in pain. Instead, figure out where the contributing factor is,” he said. “Opioids are ‘stupid’ drugs—they do not know which pathway to take, and it is not possible to target only the nociceptor pathway.”
Bruera said opioid agents are problematic in about 20 percent of cancer patients receiving them, because 20 percent of people who develop a cancer have a history of coping with their problems chemically, either with alcohol or drugs.
“These patients pose a considerable challenge to the interdisciplinary team,” he said. “We have to recognize that we are not doing such a great job at early diagnosis [of chemical coping], and so we frequently find ourselves with patients who have great difficulty.”
He advised oncologists to carefully screen patients who are going to be starting on a strong opioid for risk of alcoholism or drug abuse.
“Of course these patients will need opioids too, because they have pain, but be careful with opioid dose titration,” he said. “Use the help of palliative care colleagues in those patients who screen positive for a history of alcohol or drug abuse because the treatment of those patients will be more complex for their opioid management.”
CAGE-AID Questionnaire Simple, Effective
Prospective assessment of chemical dependence is not always accurate, Bruera said, and screening is necessary to identify the individual who is coping chemically.
A “chemical coper” is a person who uses medications in non-prescribed ways to cope with distress from anguish, suffering, or despair.
“And opioids do alleviate that suffering,” Bruera said.
Problematic alcohol use predicts for opioid chemical coping, he said, and he called the four-question CAGE-AID questionnaire a wonderful screening tool for both inpatient and outpatient practice. “If a patient scores negative, the likelihood that there will be a problem is never zero, but is way lower” than for patients who answer yes to one or more of the questions.
The CAGE-AID questionnaire was originally related to alcohol use—CAGE is an acronym for its four questions— and questions were later added regarding drug use (Adapted to Include Drugs):
- Have you ever felt you should Cut down on your drinking or drug use?
- Have people Annoyed you by criticizing your drinking or drug use?
- Have you ever felt bad or Guilty about drinking or drug use?
- Have you ever had a drink or used drugs first thing in the morning (Eye-opener) to steady your nerves or to get rid of a hangover?
“Always screen with CAGE-AID, because the alcohol questions alone do not work,” Bruera said.
He said patients should not be warned about the CAGE questions beforehand—such as, “Now we're going to ask about alcohol use”—because that reduces the predictive value to “no more than flipping a coin.”
CAGE-identified patients are significantly more likely to have a history of tobacco use or active nicotine use, he said.
“Cancer patients should have a regular assessment of the CAGE history and meticulous follow-up, and the physician should avoid refilling medication without that assessment. When treatment is successful and the patient should be experiencing less pain and therefore reducing the opioids, CAGE positivity will be a barrier to that.”
‘Being Fired Is Okay’
When dealing with a chemical coper, emphasize function and ignore pain intensity as a benchmark, Bruera said. “And avoid the ‘p’ word [pain]” when speaking with the patient, he added.
A palliative care team would emphasize non-chemical coping—i.e., counseling, exercise, social activities, spirituality, and interdisciplinary care.
And don't be afraid to set limits on the relationship: “Being fired by the patient [who demands narcotics] is okay,” Bruera said. “Be careful not to prescribe out of your area of ethical comfort.”
Bruera said he used to make the mistake of saying, “Addiction isn't a problem if you have pain,” and “Because you have pain, the opioids are not going have the effect they have when you are not having pain.”
“We've learned a lot since then,” he said.
‘Pseudo-Addiction’ Not Common
Bruera was asked from the audience about “pseudo-addition”—when a patient asks for higher doses of opioids and is suspected of drug seeking, but who is actually being under-treated. The pseudo-addicted patient's supposed aberrant behavior disappears when the appropriate dose is given.
Bruera said there are some patients in this condition, but he cautioned that they should be carefully screened with the CAGE-AID questionnaire before having their dose increased.
If it is a case of pseudo-addition, then the patient should stabilize and the behaviors disappear. But if the behaviors stop and soon reappear, it's a sign the patient is coping chemically.
Other signs pointing to aberrant opioid use include the following:
- running out of drugs too early;
- losing (or reported theft) of drugs;
- arriving impaired;
- double doctoring;
- criminal activities;
- demanding a particular type and dose of opioid; and
- acting up (including threats) and excessive pain expression during encounter.
Not Much Use for Medical Marijuana
Bruera was asked in an interview if there is a place for medical marijuana in palliative care for cancer patients. He said there are endogenous ligands to the cannabinoids and so they probably do have a physiological role.
“Many years ago we did some work with a synthetic marijuana as an anti-emetic; it had effects on the patients' perceptions and it was an anti-emetic, but not a very potent one,” he said. “There might be mild effects on appetite, emesis, or pain, but these are not even comparable to standard treatments for those adverse events, and there are considerable side effects to marijuana.
“If you ask me if there is one situation where I would prescribe either medical marijuana or any of the synthetic cannabinoids, I cannot find one.”