Abstracts

Rationale:
Levetiracetam (LVT), Lamotrigine (LTG), Lacosamide (LCM) and Topiramate (TPM) are some of the most commonly used anti-seizure medications (ASMs). There is currently limited real world data on comparative efficacy of LVT, LTG, LCM and TPM when used as monotherapy. Objective To compare the response rate, tolerability, seizure-free state of LVT, LTG, LAC and TPM monotherapy in epilepsy patients.
Method:
As part of the development of an epilepsy database, we retrospectively reviewed the electronic medical records of patients with the diagnosis of epilepsy. Patients on monotherapy of LVT, LTG, LCM and TPM were identified. ILAE classification for seizures (2017) was utilized and p-value < 0.05 was considered as statistically significant. Good tolerability was defined as no or minimal reported side effects. Seizure-free state was defined as no reported seizure three times the longest pre-intervention interval of seizures.
Results:
Out of 1665 patients, 55.79% (929) patients were on monotherapy currently. Among these patients, 291 (17.47%) patients were on LVT, 189 (11.35%) patients were on LTG, 51 (3.06%) patients were on LCM, and 64 (3.84%) patients were on TPM. Mean age of patients and age of onset of seizures did not differ significantly in the four groups of patients. LTG and TPM were most commonly prescribed ASM in women (64.6%) compared to men (34.39%). LVT was the most commonly prescribed first ASM (86.9%) while Lamotrigine was the most likely to be the ASM patients were initially switched to (25.3%). Patients’ maintenance rate on monotherapy for more than 5 years in LVT group was 61.85%, with LTG 58.73%, LCM 54.68% and TPM was 65.6%. Overall discontinuation rates as initial monotherapy trial are as following: TPM in 49/119 (43.3%), LCS in 21/72 (29.16%), LVT in 96/387 (24.87%), and LTG in 53/242 (21.9%) of patients. LTG monotherapy (29.3%) was associated with the highest seizure free rate compared to LVT (20.9%), LCM (13.9%), and TPM (17.7%), p< 0.05. Response rate of >50% was seen in 87.3% (338/387) with LVT, 87.6% (212/242) with LTG, 100% (72/72) in LCM and 81.4% (92/113) with TPM (p-NS). Similarly, good tolerability was noted in 90.9% (352/387) with LVT, 88.14 % (214/242) with LTG, 97.2% (70/72) with LCM, and 94.6% (107/113) with TPM (p-NS). Most commonly reported side effect was irritability with LVT (6.2%), rash with LTG (9.19%), dizziness with LCM (2.7%), psychomotor agitation (2.6%) with TPM.
Conclusion:
Levetiracetam monotherapy is the most commonly used initial ASMs in our practice while lamotrigine is the most often used as the first switch monotherapy. Lamotrigine monotherapy was associated with the highest seizure free rate. Dropout rates were the highest for topiramate compared to the other three ASM.
Funding:
:None