Abstracts

Rationale: To examine adherence to lacosamide (LCM), and to compare objective and subjective adherence measures, among predominantly African-Caribbean patients with epilepsy (PWE).Methods: These data are derived from an ongoing study at our institution on the effect of LCM on mood and quality of life in epilepsy patients. Adherence to LCM (always prescribed bid) was electronically monitored with the Medication Event Monitoring System (MEMS). Patients also completed the Morisky 4-item scale of medication adherence, and rated their ability to take AEDs as prescribed over the past week, two weeks, and month. Seizure frequency was self-reported. Data analysis for this preliminary report focused on Pearson s correlations and reporting adherence patterns. Results: Subjects (7 men, 6 women; mean age 39, range 18-85) were predominantly African American or African Caribbean (92.3%); 31% did not complete high school. Using the accepted criterion of a Morisky score 1 to indicate nonadherence, 46% percent of subjects were nonadherent. Reasons for nonadherence included occasional carelessness about taking AEDs (38%), followed by forgetfulness (31%). One patient reported stopping AEDs when feeling better, and none reported stopping AEDs when feeling worse. No subjects stopped LCM or missed doses due to dose-related or idiosyncratic side effects. Self-reported percent adherence on the Morisky significantly correlated with electronically monitored adherence (i.e., percent days correct LCM doses taken during prior month as measured with MEMS cap: r=0.57; p=0.043). Patients self-ratings of their ability to take LCM as prescribed also significantly correlated with MEMS data for the prior week (r=.68, p=.010) and prior two week (r=.63, p=.02) intervals. This relationship did not reach statistical significance for the prior month (r=.53, p=.061); however, this may be due to small sample size. Average adherence to LCM over a one month period, as measured by MEMS, was 70% (SD=26.8). Finally, percent adherence on the Morisky significantly correlated with self-rated adherence (1 week: r= -.70, p=.008; 2 weeks: r= -.64, p=.018). Nonadherence over a one month interval was due to both missed doses (mean=8.6; SD=10.9; range 0-37) and extra doses (mean=2.3; SD=2.1; range 0-7). Errors were more likely to occur with the evening dose than with the morning dose, and when the patient had no routine to take LCM at the same time every day. Patients experienced few seizures during the monitoring period, and some could not reliably report this information. Conclusions: Our preliminary findings indicate substantial rates of LCM nonadherence among predominantly African-Caribbean PWE. Many patients reported carelessness and forgetfulness as barriers to adherence, which suggests targets for interventions. Finally, significant relationships between self-reported and electronically monitored adherence suggest that standardized self-report adherence measures can be valuable tools for clinicians. Supported by an investigator-initiated research grant from UCB Biosciences.