Chemical coping and efficacy of buprenorphine for cancer pain.

Abstract

200 Background: The management of cancer-related pain is challenging in the age of the opioid epidemic. Patients who struggle with substance misuse or chemical coping use these substances to dull emotional and or existential suffering. Buprenorphine is often used for cancer pain due to less reported euphoria when compared to other opioids. Methods: We conducted a retrospective review of patients in an outpatient palliative care clinic at a tertiary comprehensive cancer center who were prescribed buprenorphine for cancer pain. Total oral morphine equivalent (OME), as well as use of adjuvant non-opioid neuropathic pain medication, were assessed prior to transition to buprenorphine. Chemical coping behavior was defined as patients taking opioids for emotional pain in excess of the maximum prescribed amount. Pain scores were reported before and after buprenorphine administration using a Likert pain scale (0-10). Patients were also assessed for the presence of withdrawal symptoms after transition to buprenorphine. Results: Patients were predominantly female (75%), slightly more than half had a psychiatric diagnosis (56%), a majority were on non-opioid neuropathic pain medication (93%), and the majority were identified as chemical copers (75%). For all patients, the mean pain score prior to buprenorphine (pain pre) was 8.3 and the mean pain score on follow up post buprenorphine (pain post) was 6.1, with a reduction in mean pain score (pain change) of -2.0 (p = 0.059). Patients without chemical coping behaviors reported a significantly greater reduction in pain scores compared to patients with chemical coping (pain change -5.0 vs -1.3, p = 0.02). Illicit drug use and psychiatric co-morbidity were not associated with differences in reported pain scores. Only a small number of patients reported withdrawal symptoms (6%) during buprenorphine transition. Conclusions: Rotation to buprenorphine led to a trend of reduction in pain score, though not statistically significant. Patients without chemical coping experienced greater reductions in pain score than those with chemical coping behavior. Illicit drug use and psychiatric co-morbidity were not associated with differences in reported pain.