SAN FRANCISCO – Opioids are the mainstay of pain treatment at the end of life, but using them in this population presents some challenges, Janet L. Abrahm, M.D., said at the annual meeting of the American College of Physicians.
Dr. Abrahm, codirector of the pain and palliative care program at the Dana-Farber Cancer Institute, Boston, offered a series of pearls on the topic.
▸ Chronic pain doesn't look like acute pain. A person in chronic, severe pain may not have any objective, observable signs. You have to believe the patient, and be alert for behavioral signs. For example, people in pain often guard the painful part of their bodies. They don't eat, sleep, or interact normally.
▸ Don't forget nonpharmacologic therapies. Heat, cold, and massage can all be helpful. Cold seems to work especially well with neuropathic pain. Have a family member fill a foam cup with water, freeze it, and give the patient an ice massage. Heat works well if there's a muscle spasm. Positioning is also important. Help patients take their limbs off their pressure points. Acupuncture has been clearly shown to help with pain, and cognitive-behavioral therapy also is quite effective.
▸ Pharmacokinetic studies have shown that the peak methadone level will not occur for 3–4 days after initiation. The patient will complain of incomplete pain relief for the first few days, and the physician will be tempted to start the medication at too high a dose. But starting at 10 mg three times a day will result in the patient being very sleepy by day 3.
▸ “Don't do what I did and make somebody seize from Demerol,” Dr. Abrahm said. “Demerol [meperidine] is a useless drug for chronic, severe pain.” That's due to its short half-life. A patient who uses it for a couple of days will start to show signs of opioid toxicity.
▸ Myoclonus is one of the early signs of opioid neurotoxicity. Patients may exhibit spontaneous jerking, or they may pull their hand away when touched. “At the end of life that's particularly poignant,” Dr. Abrahm commented. “You might have a family member think that her mother was pulling her hand away, and that she had done something terrible [so] that her mother wouldn't even hold her hand.” Assure the family member that it was just a reflex. Other early signs of opioid neurotoxicity are hypervigilance and hyperalgesia.
▸ If a patient experiences myoclonic jerks from opioid toxicity, it's useful to administer a liter or two of fluids to flush out some of the drug and its metabolites. Then switch the patient to an equal analgesic dose of a different opioid.
▸ Bad dreams also can signal opioid neurotoxicity. Make a practice of asking patients whether they're having nightmares or hallucinations; many will be reluctant to bring up this symptom on their own.
▸ Preventive laxatives are a must when you institute any opioid, even at the level of oxycodone. People in pain don't think about whether they've had a bowel movement. At the end of life, people can even become delirious because they're impacted. “I actually have recommended within the last 3 days of life an enema for someone who was impacted and delirious, and she quieted down and was much more comfortable after that,” Dr. Abrahm said. “The nurses took back all the bad things they said about me.”
Fiber-based laxatives don't work well in these patients because “fiber turns to cement in your gut when you're on opioids,” she said. She prefers using senna; sometimes an osmotic agent will be required. Polyethylene glycol is better than lactulose or sorbitol because it doesn't cause gas or bloating.
▸ For quick pain relief, transmucosal fentanyl can be as fast as intravenous administration. The patient puts this lollipop-like “Oralet” against the inside of his or her gums, where it's dissolved by saliva. It works within 5 or 10 minutes. Manufacturers are working on a more effervescent form of transmucosal fentanyl for patients with inadequate saliva. Patients should be cautioned not to swallow the Oralet because the liver would metabolize most of the drug in that case.
▸ Fentanyl patches also function well, but they need a subcutaneous fat reservoir to work. Elderly patients are often malnourished, and in these patients the fentanyl will simply be absorbed into the bloodstream and quickly metabolized by the liver. That makes the fentanyl patch “a very expensive Band-Aid,” in Dr. Abrahm's words.
Dr. Abrahm acknowledged serving as a consultant to or on the speakers' bureau of a number of pharmaceutical companies that market pain medications.