Lack of association between generic brittleness and neuropsychiatric measures in patients with epilepsy

In a prior bioequivalence study, generic brittle (GB) patients with epilepsy who were considered at risk of worsened seizures or drug side effects from switching antiepileptic drug (AED) formulations demonstrated no significant difference in their drug levels when switched between a brand and generic AED. An alternative basis for being GB may relate to having a personality or mindset that predisposes to poor outcomes from a formulation switch. The objective of this study was to explore whether GB patients with epilepsy could be differentiated from not GB patients based on standardized measures of personality, mood, outlook, and beliefs.

This was an exploratory, observational, case-control, non-therapeutic study in patients with epilepsy. Patient interviews were conducted, and histories were collected, yielding each patient (n = 148) to be determined as GB or not GB. Eight neuropsychiatry tests were administered to n = 127 of these patients. Tests included Neuroticism Extraversion Openness Personality Inventory 3 (NEO-PI 3), Life Orientation Test-Revised (LOT-R), Quality of Life in Epilepsy Inventory-89 (QOLIE-89), Adverse Childhood Experiences Score (ACE), Physical Symptoms Questionnaire or Patient Health Questionnaire-15 (PHQ-15), Beck Depression Inventory II (BDI-II), Beck Anxiety Inventory (BAI), and the Beliefs About Medicines Questionnaire Epilepsy (BMQ-Epilepsy). A total of 23 Chi squared analyses, along with logistical regression, were performed to assess which tests and sub-elements associated with GB status.

None of the neuropsychiatry tests or their sub-elements differentiated GB patients from not GB patients. Results implicate that standardized measures of personality, mood, outlook, and beliefs about their healthcare do not differ between GB and not GB patients with epilepsy, possibly because generic brittleness is caused by factors that neuropsychiatry tests do not measure.

We hypothesized that being GB may relate to having a personality or mindset that predisposes patients to attributing poor outcomes to a formulation switch. However, findings here in patients with epilepsy did not uncover neuropsychiatric factors that predict which patients were GB and which were not GB.