Prescriptions for newer antiseizure medications (ASMs) among Medicaid patients with epilepsy are less likely to be given to Black, Latino, and Native Hawaiian and Other Pacific Island individuals, according to findings published today in Neurology Clinical Practice.

As the primary treatment for people living with epilepsy, ASMs are catergorized into 3 generations, based on the chronology of their availability in the United States: first-generation ASMs (eg, carbamazepine, phenytoin, and valproate), second-generation ASMs (eg, gabapentin, levetiracetam, and zonisamide), and the newest third-generation ASMs (lacosamide and perampanel).

Finding the right medication is often a trial-and-error process that is based on the individual patient, noted lead study author Wyatt Bensken, PhD, of Case Western Reserve University in Cleveland, Ohio, in an accompanying press release. However, Bensken added that studies have shown that use of newer medications improves outcomes, and some newer medications have fewer adverse effects.

There has been an increase in use of third-generation ASMs, but geographic differences have been observed. “Layered on these patterns of usage is the observation that there are racial and ethnic differences in adherence to ASMs, with minoritized populations having overall lower adherence,” said the study authors.

They sought to further investigate whether there were racial/ethnic differences in use of newer ASMs, specifically 2 main outcomes: adherence to ASMs, as measured by the proportion of days covered, where less than 0.8 represents not adherent, and being on a newer-generation (second or third) ASM.

Researchers looked at 5 years (2010–2014) of Medicaid claims data from 15 states for adults who filled at least 2 prescriptions for epilepsy drugs and were in the 18-to-64 age range. Multilevel logistic regression models were used to examine the association between newer-generation ASMs and adherence. Racial/ethnic differences in ASM use were then compared in models adjusted for demographics, utilization, year, and comorbidities.

The racial/ethnic categories included American Indian or Alaskan Native (AIAN), Asian or Pacific Islander, Black, Hispanic, Native Hawaiian or Other Pacific Islander (NHOPI), Other, and White.

A total of 78,534 adults with epilepsy were included in the analysis, of which a majority, 41,975, were White; 17,729 Black; 505 AIAN; 1246 Asians; 9376 Hispanics; 1154 NHOPI; and 6549 Other. Overall, 25.6% of patients were on older, first-generation ASMs, with 65.1% on second generation and 9.3% on third generation.

Compared with White individuals, findings indicated that Black (adjusted odds ratio [aOR], 0.71; 95% CI, 0.68-0.75), Hispanic (aOR, 0.93; 95% CI, 0.88-0.99), and NHOPI individuals (aOR, 0.77; 95% CI, 0.67-0.88) had lower odds of being on newer ASMs. AIAN individuals conversely showed increased odds of being on newer ASMs compared with White patients (aOR, 1.30; 95% CI, 1.03-1.64), but the relationship was less clear for Asian individuals (aOR, 0.93; 95% CI, 0.82-1.06).

Moreover, patients who saw a neurologist (aOR, 3.26; 95%, CI, 3.13-3.41) or who had a new diagnosis (aOR, 1.29; 95% CI, 1.16-1.42) had higher odds of being on newer ASMs. Black and Hispanic individuals had lower odds of being on a newer ASM whether they saw a neurologist or not compared with White individuals.

Regarding adherence, being solely on second-generation ASMs during the study period was associated with better adherence (adjusted OR, 1.17; 95% CI, 1.11-1.23), as was being on third-generation ASM (aOR, 1.50; 95% CI,  0.61-3.67). Black individuals were shown to be the least likely to be adherent to ASMs compared with White patients (aOR, 0.62; 95% CI, 0.60-0.65), followed by Hispanic (aOR, 0.78; 95% CI, 0.74-0.82) and Asian patients (aOR, 0.81; 95% CI, 0.72-0.92).

“While further study is needed to understand these differences and the mechanisms behind them, these critical gaps in care may represent disparities that can be addressed and that warrant greater attention,” Bensken said. “Changes that could be made include increasing referrals to neurologists and exploring whether a newer drug may be as effective as an older drug but with fewer side effects, which could increase the likelihood that people take all their doses.”

The sole inclusion of patients who filled at least 2 prescriptions for epilepsy drugs was cited as a key limitation for the study findings as it excluded people with epilepsy who were untreated, a population experiencing potentially even greater inequities in care.

Reference

Bensken WP, Baca Vaca GF, Alberti PM, et al. Racial and ethnic differences in antiseizure medications among people with epilepsy on Medicaid. Neurol Clin Pract. 2023;13:e200101. doi:10.1212/CPJ.0000000000200101