Breakthrough pain in opioid-treated patients with neuropathic pain.

Abstract

OBJECTIVE: This report aims to describe the prevalence and characteristics of breakthrough pain in patients with neuropathic pain. METHODS: The study represents data from a subset of patients from a larger survey of 228 patients with chronic noncancer pain. Patients were identified from nine pain programs and were administered a telephone questionnaire. The study population comprised 45 chronic noncancer pain patients with primary neuropathic pain diagnoses who were being treated with opioids. RESULTS: Pain had been present for a median of six years. Medications used for pain in addition to opioids included nonsteroidal anti-inflammatory agents (29 percent), antidepressants (60 percent), and anticonvulsants (53 percent). Thirty-five of the patients (78 percent) described a total of 42 distinct types of breakthrough pain. The median number of episodes per day was two; the median time to maximum intensity was 10 minutes, and the median duration of pain was 60 minutes. Patients could identify a precipitant for 62 percent of the pains, and 88 percent of the precipitants were activity related. The onset of breakthrough pain could not be predicted for 48 percent of the pains and could only sometimes bepredicted for 29 percent of the pains. CONCLUSION: Breakthrough pain is common in opioid-treated patients with chronic neuropathic pain. Such pain often has a rapid onset and a relatively short duration, and it is frequently difficult to predict, similar to breakthrough pain in cancer patients.