The FDA has approved fenfluramine (Fintepla, Zogenix Inc), a Schedule IV controlled substance, for the treatment of seizures associated with Dravet syndrome in patients 2 years of age and older.

Dravet syndrome is a life-threatening, rare, and chronic form of epilepsy and is often characterized by severe, unrelenting seizures despite medical treatment, according to the FDA press release.

The safety and efficacy of fenfluramine for the treatment of seizures associated with Dravet syndrome was demonstrated in 2 clinical studies in 202 subjects between the ages of 2 and 18 years. The studies measured the change from baseline in the frequency of convulsive seizures.

Subjects treated with fenfluramine experienced significantly greater reductions in the frequency of convulsive seizures during the trials than subjects who received placebo in both studies. These reductions were seen within 3 to 4 weeks and remained generally consistent over the 14- to 15-week treatment periods.

Fenfluramine includes a boxed warning that states the drug is associated with valvular heart disease (VHD) and pulmonary arterial hypertension (PAH). According to the FDA press release, patients must have cardiac monitoring using echocardiograms performed before treatment, every 6 months during treatment, and once 3 to 6 months after treatment is discontinued.

If the echocardiogram shows signs of VHD, PAH, or other cardiac abnormalities, health care professionals must consider the benefits and risks of continuing treatment with fenfluramine for the patient.

Fenfluramine is available only through a restricted drug distribution program under a risk evaluation and mitigation strategy (REMS) due to the risks of VHD and PAH.

The fenfluramine REMS requires health care professionals who prescribe fenfluramine and pharmacies that dispense it to be specifically certified in the fenfluramine REMS. Further, patients must be enrolled in the REMS. Prescribers and patients must adhere to the required cardiac monitoring with echocardiograms to receive fenfluramine, as part of the REMS program.

The most common adverse reactions of fenfluramine in clinical studies included decreased appetite, drowsiness, sedation and lethargy, diarrhea, constipation, fatigue or lack of energy, drooling, and upper respiratory tract infection.

FDA approves new therapy for Dravet syndrome. FDA. Published June 25, 2020. Accessed June 26, 2020.