Authors :
Presenting Author: Kristen Zemina, MD – University of South Florida
Justin Cole, BS – University of South Florida
Stephen Hofmann, MD – University of South Florida
Ushtar Amin, MD – University of South Florida
Marina Azevedo, BS – University of South Florida
Angélica Rivera-Cruz, MD – University of South Florida
Selim Benbadis, MD – University of South Florida
Rationale:
Purified cannabidiol (Epidiolex, CBD) and fenfluramine (Fintepla, FFA) are approved by the FDA for the same indications: Lennox Gastaut syndrome (LGS) and Dravet syndrome. They have distinct mechanisms of action. Our purpose was to review patients taking the combination of CBD and FFA and provide a summary of our experience at a level 4 epilepsy center.
Methods:
We performed a retrospective chart review of patients who were prescribed CBD and FFA at our epilepsy center. Seizure frequency and seizure intensity were the primary outcomes assessed. Secondary outcomes related to tolerability, including duration of treatment retention and the occurrence of adverse effects (AEs), were also described. Patients who were not concomitantly on both CBD and FFA were not included in the final analysis.
Results:
A total of 26 patients were identified as having been prescribed both CBD and FFA with all patients having started CBD first. Only 16 patients had a period of concomitant use of both CBD and FFA. See Figure 1. The duration of this overlap varied from 0.25 – 45 months. 13 patients carried a diagnosis of LGS and 3 of Dravet syndrome. Patients aged from 20-52 years old, with a slight male predominance (9 men and 7 women). Ten of our patients remain on both CBD and FFA. All ten patients reported subjective improvement in seizure frequency or reduced intensity. Of the 6 patients who stopped either CBD or FFA, perceived ineffectiveness was the most commonly cited reason. Only two patients who remain on both CBD and FFA reported side effects during routine clinic follow ups. See figure 2. One patient underwent total corpus callosotomy (CC) and another had a deep brain stimulator (DBS) placed while on the combination of CBD and FFA – both ultimately went on to discontinue one of these medications.
Conclusions:
Approximately 63% of patients in our population reported improved seizure frequency or reduced intensity of seizures on the combination of CBD and FFA. Only 20% of patients who remained on the combination reported side effects, while 100% who stopped either CBD or FFA described side effects during follow up visits. When reviewing efficacy and adverse effects, there were confounding factors including the addition of or dose changes of other anti seizure medications and the pursuit of surgical intervention (CC) or neuromodulation (namely DBS). Another challenge was the limited ability to have structured follow up intervals as the date of medication prescription could not be substituted for the date of medication initiation and specific start dates were not documented.
Though more data is needed, our limited experience suggests that the concomitant use of CBD and FFA is generally well tolerated and may offer improved seizure control in the majority of patients who trial the combination.
Funding: None.