Caused by the same herpes zoster virus that causes chicken pox, shingles and its bouts of painful rashes on the body, limbs and face yield severe nerve pain at the sites of the healed rash.
Fearful that opiates would create dependency or mental disturbance in the elderly, physicians have been reluctant to prescribe the painkillers for the treatment of such persistent pain. But reporting in the Oct. 8 issue of Neurology, a team of Hopkins pain researchers demonstrate that in 76 seniors, opiates provided relief for the nerve pain, called postherpetic neuralgia (PHN), without any of these side effects.
"By comparing opiates to antidepressants head to head, our study suggests that opiates effectively relieve pain and are preferred by a greater proportion of patients," says anesthesiologist Srinivasa N. Raja, M.D., lead author of the study and director of pain research at Hopkins. "This adds further evidence that opiates are a good alternative for patients not responding to other types of pain medications."
Raja and colleagues studied the PHN patients from 1995 to 1999. The patients' average age was 71; 45 percent were male. All had PHN for at least three months following the shingles rash. Fifty-seven had increased sensitivity to touch, eight had increased sensitivity to cold and 14 had increased sensitivity to heat.
Researchers evaluated each patient's neurologic and mental health. In a series of three eight-week periods, each patient took either an opiate, an antidepressant or a placebo.
A pharmacist prepared the medications in identical gel capsules and mailed them straight to the participants' homes, so neither they nor the researchers knew in which order the medications would be taken. Patients started with one pill a day at bedtime and gradually increased until they experienced maximum pain relief or ill side effects. Researchers then followed up with each patient twice a week through telephone surveys. Forty-four of the 76 patients completed all three parts of the study. Thirty-eight percent reported pain relief with opioids, compared to 32 percent who had relief from antidepressants and 11 percent with relief from placebo. More patients said they preferred the opiate (54 percent) to the antidepressant (30 percent). Some patients dropped out during the opiate portion of the study because of bad side effects or because their family members expressed concern they would become dependent on the medications.
The most common side effects were constipation, nausea, dizziness, drowsiness, loss of appetite and dry mouth. These were more common from opiates than the other medications.
The study was funded by the National Institutes of Health. Co-authors were J.A. Haythornthwaite, Ph.D.; M. Pappagallo, M.D.; M.R. Clark, M.D.; T.G. Travison, Ph.D.; S. Sabeen, M.D.; R.M. Royall, Ph.D.; and M.B. Max, M.D.
Raja is a paid consultant to Purdue Pharma L.P. This relationship, which did not exist at the time the study was completed, is being managed by The Johns Hopkins University in accordance with its conflict-of-interest policies.
Raja, S.N. et al, "Opioids versus antidepressants in postherpetic neuralgia: A randomized, placebo-controlled trial," Neurology, Vol. 59: pages 1015-1022.
Related Web site:
Facial neuralgia resources
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