Abstracts

Rationale: Levetiracetam (LEV) is a second generation anti-epileptic drug (AED) commonly chosen as first-line treatment for epilepsy. Known side effects are behavioral including mood dysfunction and irritability, along with fatigue. The risk of behavioral side effects is often quoted near 20%, but when patients are evaluated in the Epilepsy Monitoring Unit (EMU), these side effects are reported at high proportions, resulting in patients being transitioned to alternative agents. Our aim is to discover the prevalence of behavioral side effects from LEV in EMU patients and determine the AEDs used most commonly when transitioning medications. Methods: A retrospective chart review was conducted searching for patients aged 16-99 years admitted to Mayo Clinic Arizona over the last 8 years (2011-2019). Patients admitted to the EMU on maintenance LEV were included. Patients with recurrent admissions were included and evaluated independently. Patients were excluded for the following reasons: final diagnosis of non-epileptic spells, admission for intracranial monitoring, and admission from an outside facility for ictal SPECT scan only. Results: Two hundred and ten admissions were identified of patients on maintenance LEV at time of admission to the EMU. The most common indication was for pre-surgical evaluation 64/210 (30.5%), followed by seizure localization 52/210 (24.8%), spell classification 50/210 (23.8%), medication management 28/210 (13.3%), and seizure quantification 12/210 (5.7%). 150/210 (71.4%) were diagnosed with focal epilepsy and 60/210 (28.6%) generalized epilepsy. The average total daily dose of LEV was 2,194.5mg (range, 500-5500mg). The majority 106/210 (50.5%) reported at least one side effect described as irritability 33/210 (15.7%), unspecified mood disturbance 35/210 (15.2%), increased anxiety 13/210 (6.2%), worsening depression 17/210 (8.1%), fatigue 11/210 (5.2%), or suicidal ideation 5/210 (2.4%). Overall, the rate of at least one behavior side effect was 46.7%. Of those with side effects, 47/106 (44.3%) had a known psychiatric diagnosis, the majority depression. While admitted, 74/106 (69.8%) were initiated on a new AED. Of those 74, at the time of discharge, instructions were to wean or discontinue LEV in 58/74 (78.4%). LEV was monotherapy at time of admission for 43/74 (58.1%) of these patients. The AEDs most commonly initiated prior to discharge were lamotrigine in 32/74 (43.2%), lacosamide in 11/74 (14.9%), zonisamide in 8/74 (10.8%), and clobazam in 8/74 (10.8%). Conclusions: Our results suggest reported side effects from LEV are greater than previously reported at the time of EMU admission, seen at 50.5% in our population. Although LEV side effects ranged from mild to severe, it is important to recognize that even mild behavioral complications from LEV can be impactful to a patient’s quality of life. LEV is often transitioned to an alternative agent in the EMU with lamotrigine (43.2%) being the most common in our population. Of those with reported side effects, 44.3% had a prior psychiatric diagnosis. Although a comorbid psychiatric illness does not necessarily predispose patients to behavioral complications from LEV, it must be considered when introducing a medication with potential to exacerbate these symptoms. We recommend at minimum discussion with patients regarding risk of behavioral side effects when initiating LEV and follow up specifically regarding side effects after the patient has been on maintenance LEV. When necessary, transition to an AED with a lower incidence of adverse mood effects should be considered. Funding: No funding