VANCOUVER, BC--How much insulin do you give a patient with diabetes--as much as is required to control blood sugar. "The same is true for opioids and patients with cancer pain, "Richard B. Patt, MD, said at a symposium held in conjunction with the 8th World Congress on Pain. "The only difference is we don't have a blood test to measure a patient's opioid requirement the way we do with insulin."
VANCOUVER, BC--How much insulin do you give a patient with diabetes--asmuch as is required to control blood sugar. "The same istrue for opioids and patients with cancer pain, "RichardB. Patt, MD, said at a symposium held in conjunction with the8th World Congress on Pain. "The only difference is we don'thave a blood test to measure a patient's opioid requirement theway we do with insulin."
Dr. Patt, director of Anesthesia Pain Services at The Universityof Texas M.D. Anderson Cancer Center, argues that there is a "dualstandard" in the management of pain versus other medicalproblems. "We wouldn't talk about withholding a diabeticpatient's insulin to build his character," he said, althoughphysicians routinely mete out opioids in inadequate doses.
Nonetheless, huge strides have been made in recent years in thetreatment of cancer pain, and Dr. Patt believes that medicineis at the beginning of a movement to medicalize pain treatment,"not in the sense of ignoring the psychological, behavioral,and environmental aspects of the experience of pain but simplyto encourage physicians to address pain as a legitimate medicaldisorder."
He pointed out that management of a patient who presents withpain should involve all the same steps that would be used if thepatient had a cardiovascular or gastrointestinal problem.
"Consider the differential diagnosis," he said, "doa diagnostic workup to determine the cause of the problem, formulateand discuss with patients and their families a treatment planthat includes contingencies should the primary treatment be unsuccessful,and develop a plan for serial assessment of the problem."
Instead, he said, patients with pain are often simply handed aprescription for an opioid with very little explanation. "Thisis at the heart of the myth of opioid allergy," he said.Without proper education about what to expect from opioid treatment,the patient may assume that he is "allergic" to opioidswhen normal, manageable side effects such as nausea occur. "Thepatient calls the nurse and says, I'm allergic to codeine or morphine,and ends up with a sticker on his chart that may be hard to remove."
Pain patients referred to the Pain and Symptom Management Programat M.D. Anderson often come in with "a hodgepodge of analgesicdrugs, dosages, and schedules that don't make sense," Dr.Patt said. Their regimen may include contradictory formulas, forexample, narcotic agonists and antagonists.
"If insulin or antibiotics were prescribed in this incorrectfashion, the prescriber would need to answer to a quality assuranceinitiative," he said, "but we don't seem to apply thatstandard when it comes to opioids."
The appropriate way to dose with opioids, he said, is to graduallyincrease the dose until either comfort is achieved or unacceptableside effects occur. If the side effects occurs first, then theside effects should be treated aggressively.
Common side effects such as constipation and nausea can be treatedsymptomatically, and Dr. Patt argues that one of the most fearedside effects, cognitive failure, can also be treated readily inmany cases with psychostimulants.
Unfortunately, like opioids, psycho-stimulants represent "anotherhighly stigmatized drug category," Dr. Patt said. Becauseof regulatory requirements and other concerns, psychostimulantsare rarely prescribed for patients taking opioids except in tertiarycare centers.
When side effects of a systemic opioid are truly dose limiting,physicians should think about rotating the analgesics and usingadjuvant analgesics in an attempt to reduce the opioid dose beforemoving on to more invasive procedures.
"We need to define what we mean by failure of systemic therapy,"Dr. Patt said. "What really is an adequate trial of systemanalgesics? Is dramatic failure of a single opioid drug sufficientto declare failure? Do you need failure of one, two, or threealternative opioids? Have trials of mechanism-specific agentsbeen instituted? Have psychostimulants and other symptomatic therapiesbeen initiated?"
He acknowledged, however, that cancer pain can rarely be eliminatedaltogether. "Most of what we're doing is achieving a favorablebalance between pain and side effects," he said.
He also pointed out that the three-step WHO analgesic ladder can,in fact, be accessed at any step. "One of the biggest changeswe are seeing is earlier and earlier use of strong opioids,"he said.