Dementia Medications and Their Association with Pain Medication Use in Medicare Beneficiaries with Alzheimer's Disease/Alzheimer's Disease-Related Dementias and Chronic Pain.

Abstract

Introduction: Chronic pain is prevalent among older adults with Alzheimer's disease (AD) and Alzheimer's disease-related dementias (ADRD). Memantine and acetylcholinesterase inhibitors (ACHEI; donepezil, rivastigmine, and galantamine) are approved for the treatment of dementia symptoms and may also have analgesic properties. However, findings on the clinical utility of these dementia medications for chronic pain treatment are mixed, and little is known about differences in the use of pain medication according to whether an older adult with AD/ADRD is using dementia medications.

Methods: We selected a 20% national sample of Medicare enrollees with a diagnosis of AD/ADRD and chronic pain in 2020. We calculated the odds of having any pain management prescription (opioids, serotonin and norepinephrine reuptake, gapapentinoids, or non-steroidal anti-inflammatory drugs), having an opioid prescription, and having a long-term (≥ 90 days) opioid prescription, by dementia medication (none, memantine, ACHEI, or memantine and ACHEI).

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. Over 70% of all patients had a pain management prescription. The percentage of patients who had an opioid prescription ranged from 54.5% for those without a dementia medication prescription to 44.0% for those with a prescription for both memantine and ACHEI. Similarly, the percentage of patients who had a long-term opioid prescription was highest for those without a dementia medication prescription (12.2%) and lowest for those with a prescription for both memantine and ACHEI (8.8%). Having a prescription for memantine only was associated with lower odds of 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 lower odds of having an opioid prescription (p < 0.05). Lastly, having a prescription for either memantine (OR: 0.85; 95% CI 0.77-0.94), ACHEI (OR: 0.92; 95% CI 0.86-0.98), or both (OR: 0.83; 95% CI 0.77-0.90) was associated with lower odds of having a long-term opioid prescription.

Discussion: Older adults with co-occurring AD/ADRD and chronic pain who were on dementia medications had lower odds of being prescribed opioid analgesics. Memantine and ACHEIs should be explored as potential opioid-sparing medications for older adults with AD/ADRD, given their relatively safe profiles. Future studies are needed to examine repurposing dementia medications for pain treatment.