Question

A child with Dravet syndrome is started on fenfluramine for seizure control. Which of the following must be specifically monitored during therapy?

• A. Cardiovascular status (echocardiography for valvulopathy/pulmonary hypertension)
• B. Agranulocytosis
• C. Hepatic failure
• D. Renal failure

Hint:

Remember why fen-phen was pulled from the diet-pill market.

Answer 1

The Correct Option is A

Step 1: Drug and indication. Fenfluramine is approved for seizures associated with Dravet syndrome (and Lennox-Gastaut syndrome). It acts via serotonin (5-HT) release and agonism at 5-HT receptors plus sigma-1 activity.

Step 2: Class-specific toxicity. Fenfluramine was historically withdrawn as an appetite suppressant because of serotonin-mediated cardiac valvulopathy and pulmonary arterial hypertension. Even at antiseizure doses this risk mandates cardiac monitoring - baseline and periodic echocardiography to detect valvular regurgitation and pulmonary hypertension. This makes option 1 correct.

Step 3: Why the others are wrong. Agranulocytosis is characteristic of clozapine/carbamazepine, not fenfluramine (option 2 wrong). Idiosyncratic hepatic failure is the concern with valproate/felbamate (option 3 wrong). Significant nephrotoxicity is not a defining fenfluramine effect (option 4 wrong).

Key fact: Echocardiographic cardiovascular monitoring (valvulopathy and pulmonary hypertension) is the mandated safety surveillance for fenfluramine.