About fenfluramine
Serotonin-releasing antiseizure medicine
Used for
- Treats seizures associated with Dravet syndrome.
- Treats seizures associated with Lennox–Gastaut syndrome.
Usual adult dose
Usually starts at 0.1 mg/kg twice daily; increased gradually according to response, up to 0.35 mg/kg twice daily for Dravet syndrome or 0.35 mg/kg twice daily for Lennox–Gastaut syndrome, with maximum daily limits.
Usual dose in children
For children aged 2 years and older, usually starts at 0.1 mg/kg twice daily; increased gradually according to response, with syndrome-specific maximum daily limits.
Common side effects
- Decreased appetite and weight loss
- Diarrhea, vomiting, or constipation
- Sleepiness, tiredness, or weakness
- Increased blood pressure
Important warnings
- Can cause serious heart valve disease or pulmonary arterial hypertension; heart monitoring is required.
- May cause sleepiness and impair alertness; avoid driving until effects are known.
- Do not stop suddenly; seizures may worsen.
- Controlled medicine with misuse potential; follow prescribing and dispensing requirements.
Pregnancy
Human pregnancy information is limited. Potential fetal risk is uncertain; discuss treatment risks and benefits with a specialist.
Breastfeeding
It is unknown whether fenfluramine passes into breast milk. Breastfeeding decisions should consider potential infant effects and seizure control.
Interactions
- Stiripentol with clobazam can increase fenfluramine exposure; dose adjustment may be needed.
- Strong CYP1A2 or CYP2D6 inhibitors can increase exposure.
- Serotonergic medicines may increase the risk of serotonin syndrome.
- Alcohol and sedating medicines can worsen sleepiness.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.