Opioid Rotation, Methadone Urged for Hard-to-Treat Cancer Pain

BOSTON—Most advanced cancer patients suffer from pain that could be relieved with broader use of opioid analgesics, according to Eduardo Bruera, MD, F.T. McGraw Chair in the Treatment of Cancer, M.D. Anderson Cancer Center.

Dr. Bruera told oncologists at the 14th international meeting of the Multinational Association for Supportive Care in Cancer (MASCC) and International Association for Oral Oncology (ISOO) that they should learn how to rotate opiates when one stops working—and consider prescribing methadone. He also urged them to administer painkillers rectally and by subcutaneous injection instead of resorting to intravenous delivery when pills are no longer effective.

Dr. Bruera said that a key problem is diminishing effectiveness of opioids over time despite escalating doses. Sometimes patients also develop neurotoxicity. Instead of relying on just one opioid analgesic, oncologists should develop expertise in the use of two or three that can be rotated when one fails, he said.

"The good news is, most opioids are a good alternative to the existing opioid," he told ONI. "There’s no clear idea that one is better, or that a second one is better than the one the patient was getting. So you have a lot of options according to your expertise."

Changing opioids is complicated, however. Dr. Bruera warned that doses are not equivalent from one to another. "It’s not easy to predict how much of the new opioid the patient is going to need by just looking at how much of the previous opioid the patient is using," he said.

He recommended that the physician be ready to adjust the dose of the new medication up or down. For the first 3 or 4 days after the switch, either the doctor or a nurse should call the patient frequently to ask whether he or she is sleepy or in pain. "After that, you can relax," Dr. Bruera said.

Methadone: The Ferrari of Opioids

For many patients as well as physicians, methadone is tainted by its use in maintenance programs for heroin addicts, Dr. Bruera said. Yet he recommended it enthusiastically. "Methadone is a wonderful low-cost drug. It can last a long time. The main limitation is when you start that drug, you have to be cautious," he said, describing methadone as more powerful and consequently more difficult to use than other agents.

"It’s a Ferrari Formula One," he said. "If you’re used to driving Jeeps, you use all the other painkillers. Suddenly, you’re in a Ferrari and you may skid and hit the wall. So you need to know how to drive that Ferrari before you get in."

Another obstacle to wider use of methadone and other opioids that have been available for a long time is that they are off patent and thus are relatively cheap for patients in the United States and other developed countries, Dr. Bruera said. No drug company stands to profit by promoting them, he said, characterizing methadone as an orphan drug without a sponsor.

The administration of painkillers is also an area where effective, low-cost methods are underused, Dr. Bruera said. Giving painkillers intravenously is expensive, uncomfortable, and can lead to infection, he said. Yet this method is far more widely used than alternatives when giving a pill is not an option. "Rectal and subcutaneous routes are low cost. They are effective in the community. They are safe," he said. "Think about those routes when you need to take your patient off pills."