fenfluramine
Valvular Heart Disease and Pulmonary Arterial Hypertension
Fenfluramine can cause valvular heart disease (VHD) and pulmonary arterial hypertension (PAH). There is a known association between serotonergic drugs with 5-HT2B receptor agonist activity, including fenfluramine (the active ingredient in fenfluramine), and valvular heart disease and pulmonary arterial hypertension. Although no patients receiving fenfluramine developed valvular heart disease or pulmonary arterial hypertension in clinical trials for DS and LGS of up to 3 years in duration, cases of valvular heart disease and pulmonary arterial hypertension have been reported during use of fenfluramine in the postmarketing setting [see Boxed Warningand Adverse Reactions (6.1)] .
Because of this risk, cardiac monitoring is required prior to starting treatment, during treatment, and after treatment with fenfluramine concludes .Cardiac monitoring via echocardiogram can identify evidence of valvular heart disease and pulmonary arterial hypertension prior to a patient becoming symptomatic, aiding in early detection of these conditions.
Monitoring data
Prior to starting treatment, patients must undergo an echocardiogram to evaluate for valvular heart disease and pulmonary arterial hypertension.
Echocardiograms should be repeated every 6 months, and once 3-6 months post-treatment with fenfluramine.
The prescriber must consider the benefits versus the risks of initiating or continuing treatment with fenfluramine if any of the following signs are observed via ECHO:
Valvular abnormality or new abnormality via echocardiogram.
VHD as indicated by mild or greater aortic regurgitation or moderate or greater mitral regurgitation, with additional characteristics of VHD (e.g., valve thickening or restrictive valve motion).
PAH as indicated by elevated right heart/pulmonary artery pressure (PASP > 35 mm Hg).