Investigators hypothesize that concurrent symptoms of anxiety and depression may be linked to concerns about adverse events.
The results of a new study show that nearly half of patients with epilepsy would oppose a generic substitution of their antiseizure drug (ASD), and almost three-fourths would be concerned about adverse events after switching to a generic.
Generic substitution of ASDs has been controversial for many years, according to the study authors. Findings from some research have indicated dubious tolerance for generic ASDs. However, results of most prospective studies of generic ASD substitution have found that generics are well tolerated, with similar proportions of patients who revert to branded drugs compared with generic substitution of non-ASDs. Despite these findings, the study authors said that many patients still have concerns about generic substitutions.
To better understand why patients with epilepsy may be skeptical about generic drugs, the investigators conducted a cross-sectional survey of adults with epilepsy using the branded drugs lamotrigine (Lamictal), levetiracetam (Keppra), pregabalin (Lyrica), or topiramate (Topamax).They assessed symptoms of anxiety and depression, beliefs about medications, and sense of self-efficacy. Caregivers were asked to answer questions for individuals with communicative or intellectual disabilities.
According to the survey results from 178 participants, 46% said they would oppose generic substitution if suggested by their neurologist and 71% would worry about adverse effects or increased seizure frequency after a switch. Furthermore, the investigators found that being 50 years or older increased the odds of opposing generic substitution.
More importantly, the investigators said some evidence suggested worse substitution outcomes for elderly patients who substitute a generic. Switching to an alternative ASD compound was associated with a higher risk of seizures in a study whose population had a mean age of 54 years, but not in a younger population with a mean age of 34 years, according to earlier studies.
The study authors noted that cognitive comorbidities and polypharmacy among older adults may affect adherence and vulnerabilities to changes in medications. However, high-quality evidence is lacking and the potential correlation between age and generic ASD substitution outcomes needs further investigation.
Interestingly, caregivers also expressed concerns about adverse effects or increased seizure frequency. Of the 22 caregivers who answered the questionnaire, 21 expressed concerns, a much higher proportion than patients who answered the questions themselves. These findings are in line with the results of earlier studies, in which 60.7% of caregivers had negative opinions about generics.
The investigators hypothesized that concurrent symptoms of anxiety and depression could be linked with concerns about adverse events following a generic substitution, though they found none of those associations. It is possible that more severe symptoms could have different results, but according to the investigators their chosen cut-offs for depressive symptoms likely reflect different severities.
Based on these findings, the investigators said that pharmacists and other health care providers should consider patients’ individual demographics and work to allay their concerns about substituting generic ASDs. Concerns are more common in older adults, although many caregivers also had worries about adverse events, so identifying how to approach negative outcomes is an important future field of research.
Olsson P, Pearson K, Reimers A, Källén K. Widespread skeptic atti- tudes among people with epilepsy toward generic antiseizure drugs—a Swedish survey study. Epilepsy Behav. 2021;114(pt A):107554. doi:10.1016/j.yebeh.2020.107554