(098) Dementia Medications and their Association with Pain Medication Use in Medicare Beneficiaries with Dementia and Chronic Pain

Background: Chronic pain is highly prevalent among older adults with Alzheimer’s disease and related dementias (ADRD). Memantine and acetylcholinesterase inhibitors (ACHEI; donepezil, rivastigmine, and galantamine), approved for the treatment of dementia symptoms, may also have analgesic properties. However, findings on the clinical utility of these dementia medications for the treatment of chronic pain are mixed.

Objectives: To assess the effect of dementia medications on frequency and patterns of pain medication prescriptions among Medicare beneficiaries with ADRD and chronic pain.

Methods: A 20% national sample of Medicare enrollees with a diagnosis of ADRD and chronic pain in 2020 were selected. We included those with Part A, B, and D enrollment for all 12 months of 2020 and complete demographic information. Our exposure was dementia medication prescriptions, categorized as none, memantine only, ACHEI only, or both memantine and ACHEI. Our outcome was pain medication prescriptions, which included prescription opioids, serotonin and norepinephrine reuptake inhibitors (e.g., duloxetine, venlafaxine), gapapentinoids (gabapentin and pregabalin), and non-steroidal anti-inflammatory drugs. We used logistic regression models to assess the odds of 1) having any pain management prescription and 2) having an opioid prescription, by dementia medication group. We controlled for age, sex, race/ethnicity, region, original entitlement, dual Medicaid coverage, comorbidities, and pain location.

Results: Among 103,564 patients, 5.5% received a memantine prescription, 14.4% received an ACHEI prescription, and 8.6% received a prescription for both. About 54.5% of those without a dementia medication, 46.6% of memantine users, 47.5% of ACHEI users, and 44.0% of users of both had an opioid prescription. In adjusted analyses, having a prescription for memantine only was significantly associated with lower odds of having any pain management prescription [odds ratio (OR): 0.94, 95% confidence interval (CI): 0.88, 1.00, p< 0.05]. Having a prescription for either memantine (OR: 0.79; 95% CI: 0.75, 0.84), ACHEI (OR: 0.85; 95% CI: 0.82, 0.89), or both (OR: 0.75; 95% CI: 0.72, 0.79), was associated with significantly lower odds of having an opioid prescription (p < 0.05).

Conclusions: Dementia medications were associated with lower odds of having an opioid prescription. Also, memantine alone was associated with lower odds of having any pain medication prescription. These dementia medications should be further explored as potential opioid-sparing medications, given their relatively good safety profile. Future studies are needed to examine the potential for repurposing dementia medications for pain treatment.