Authors :
Presenting Author: Varun Kumar, MD – University of South Florida Morsani College of Medicine, Tampa, FL, USA
Ushtar Amin, MD – Department of Neurology – University of South Florida Morsani College of Medicine, Tampa, FL, USA; Angelica Rivera-Cruz, MD – University of South Florida Morsani College of Medicine, Tampa, FL, USA; Marina Azevedo, BSc – University of South Florida Morsani College of Medicine, Tampa, FL, USA; Selim Benbadis, MD – University of South Florida Morsani College of Medicine, Tampa, FL, USA
Rationale:
Fenfluramine is one of the most recently available antiseizure medications (ASM). It was approved for the treatment of Lennox-Gastaut syndrome (LGS) in March 2022 and for Dravet syndrome in June 2020. The goal of this study was to review the use of fenfluramine (FFA) at a typical adult epilepsy center.
Methods:
We reviewed all patients who were prescribed FFA at our adult epilepsy center after it was approved by the FDA for LGS in March 2022. Data were collected through chart review and by telephone calls to either the patient or the caregiver regarding drug effectiveness, overall satisfaction, and adverse events.
Results:
We identified 13 patients. Five (39%) were female, mean age was 24 years, and mean weight was 72.8 kg. Eleven patients (85%) had a diagnosis of LGS (27% genetic cause, 73% unknown cause), and two patients (15%) had a diagnosis of Dravet syndrome.
Mean number of concomitant ASMs was four. Of those, the most common were pharmaceutical CBD (77%), clobazam (54%), lacosamide (31%) and lamotrigine (31%).
Three patients (23%) never initiated FFA due to theoretical side effects such as valvular heart disease and the requirement for continued echocardiogram. Four (54%) patients discontinued FFA within 1 week due to side effects such as rash, diarrhea, or behavioral changes. Six patients (46%) continued to take FFA and had improvement with decreased duration of seizures, improved behavior, and stable seizure frequency. Due to limited mobility and static encephalopathy, all 6 caregivers reported difficulty quantifying seizure frequency and overall reported improved behavior and stable seizure events.
The most commonly reported side effects were fatigue, diarrhea, somnolence, appetite suppression, and rash.
Retention rate at 14 weeks was 46%.
Conclusions:
In this small study of a patient population similar to that of clinical trials, we found an improvement in seizure duration and behavior, but an unclear impact on seizure frequency. A significant proportion of patients did not initiate the medication or completed the titration due to cardiac concerns or minor adverse events.
Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.