It was used both on its own and, in combination with phentermine, as part of the anti-obesity medication Fen-Phen.In June 2020, fenfluramine was approved for medical use in the United States with an indication to treat Dravet syndrome.The effectiveness of fenfluramine for the treatment of seizures associated with Dravet syndrome was demonstrated in two clinical studies in 202 subjects between ages two and eighteen. The studies measured the change from baseline in the frequency of convulsive seizures. In both studies, subjects treated with fenfluramine had significantly greater reductions in the frequency of convulsive seizures during the trials than subjects who received placebo (inactive treatment). These reductions were seen within 3–4 weeks, and remained generally consistent over the 14- to 15-week treatment periods.The U.S. Food and Drug Administration (FDA) granted the application for fenfluramine priority review and orphan drug designations. The FDA granted approval of Fintepla to Zogenix, Inc.On 15 October 2020, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Fintepla, intended for the treatment of seizures associated with Dravet syndrome. Fenfluramine was approved for medical use in the European Union in December 2020. Society and culture
Recreational use
Unlike various other amphetamine derivatives, fenfluramine is reported to be dysphoric, "unpleasantly lethargic", and non-addictive at therapeutic doses.
Medical uses
Seizures
Fenfluramine is indicated for the treatment of seizures associated with Dravet syndrome and Lennox–Gastaut syndrome in people age two and older.Dravet syndrome is a life-threatening, rare and chronic form of epilepsy. It is often characterized by severe and unrelenting seizures despite medical treatment. Obesity
Fenfluramine was formerly used as an appetite suppressant in the treatment of obesity, but was withdrawn for this use due to cardiovascular toxicity. Adverse effects
The most common adverse reactions in people with seizures include decreased appetite; drowsiness, sedation and lethargy; diarrhea; constipation; abnormal echocardiogram; fatigue or lack of energy; ataxia (lack of coordination), balance disorder, gait disturbance (trouble with walking); increased blood pressure; drooling, salivary hypersecretion (saliva overproduction); pyrexia (fever); upper respiratory tract infection; vomiting; decreased weight; risk of falls; and status epilepticus.The U.S. Food and Drug Administration (FDA) fenfluramine labeling includes a boxed warning stating the drug is associated with valvular heart disease (VHD) and pulmonary arterial hypertension (PAH). Because of the risks of VHD and PAH, fenfluramine is available only through a restricted drug distribution program, under a risk evaluation and mitigation strategy (REMS). The fenfluramine REMS requires health care professionals who prescribe fenfluramine and pharmacies that dispense fenfluramine to be specially certified in the fenfluramine REMS and that patients be enrolled in the REMS.