Opioid Exposure Negatively Affects Antidepressant Response to Venlafaxine in Older Adults with Chronic Low Back Pain and Depression.

OBJECTIVE: Serotonin norepinephrine reuptake inhibitors (SNRIs) are commonly co-prescribed with opioids for chronic pain. The purpose of this study was to describe pain and mood response to venlafaxine among older adults with chronic low back pain (CLBP) and depression relative to opioid exposure.

DESIGN: Secondary analyses were collected from a randomized clinical trial testing a stepped-care approach to comorbid pain and depression in older patients: the Addressing Depression and Pain Together study (ADAPT: 2010-2016).

SETTING: University-based late-life mental health research clinic.

SUBJECTS: Two hundred twenty-seven adults aged 65+ years with CLBP and depression.

METHODS: Participants received six weeks of lower-dose venlafaxine (≤150 mg/d). Pain and depression were measured each week. Response for both pain and depression at the end of six weeks was defined by a ≥30% improvement on a 0-20 numeric rating scale for low back pain and a Patient Health Questionnaire-9 score ≤5. Opioid exposure was analyzed as prescribed (yes or no) and by morphine equivalent dosing (MED).

RESULTS: Patients co-prescribed an opioid were less likely to report a pain response to venlafaxine. MED was negatively correlated with pain response. Depression response was not impacted.

CONCLUSIONS: Opioids are negatively associated with older adults' early analgesic response to lower-dose venlafaxine. These findings suggest that clinicians may wish to consider either nonopioid or alternative antidepressant approaches to pain management in these complex patients. It is reassuring that opioids do not prevent depression response. Future research should examine both longer duration of treatment and a wider range of doses.