Optimizing DMARD Use in Older Adults with Rheumatoid Arthritis

SAN DIEGO—Older adults with rheumatoid arthritis (RA) comprise two groups: those who have lived with diagnosed RA since an early age (young-onset RA) and those who have new-onset RA diagnosed at an older age (≥65 years), known as late-onset RA or, formerly, as elderly onset RA.¹ Individuals with late-onset RA have more acute and systemic presentation of symptoms than individuals with young-onset RA.¹ The more striking and concerning difference, from a treatment perspective, is that individuals with late-onset RA are less likely than individuals with young-onset RA to be treated with disease-modifying anti-rheumatic drugs (DMARDs), which are the standard of care for RA.

RA treatment guidelines recommend a treat-to-target approach, with early, aggressive use of DMARDs to prevent chronic deformity and disability.² Although we lack age-specific guidelines, studies have shown that treat to target is effective and achievable in late-onset RA, with an acceptable safety profile.

Evidence suggests, however, that we are far from achieving this goal in usual care for older adults. Lee and colleagues [Editor’s note: research by one of the authors] found that less than 30% of older Medicare beneficiaries with a new diagnosis of late-onset RA are started on some form of DMARD within a year of diagnosis.³ This is in contrast to 70–80% of younger adults with RA receiving DMARDs. Other studies have also reported that older adults receive less aggressive RA care.⁴

Why is DMARD utilization in late-onset RA low? Are we mistreating older adults, or do barriers exist in the real world that prevent DMARD utilization in older adults? Several real-world challenges were reviewed in the session titled Are You Ready for the Silver Tsunami? at ACR Convergence 2023, which we summarize here.

DMARDs in the Real World

Physiologic challenges

Aging is a physiologic process associated with changes in dynamic biological, environmental, psychological, behavioral and social processes that lead to irreversible functional decline across all biologic systems.⁵ The multisystem decline in function affects drug pharmacokinetics and pharmacodynamics. For example, renal blood flow and glomerular filtration rates are reduced with aging, even in the absence of any underlying pathology.⁶ Thus, serum creatinine as a sole measure of renal function can be inadequate and misleading in older adults. It is best to calculate the creatinine clearance to inform medication dosing in older adults, especially those medications that are excreted renally. Methotrexate, the first-line DMARD for moderate to severe RA, almost exclusively has renal excretion. It is no surprise that studies of methotrexate use in older adults report use of lower doses (~10 mg/weekly).⁷