About fenfluramine
Serotonin-releasing antiseizure medicine
Used for
- Seizures associated with Dravet syndrome
- Seizures associated with Lennox–Gastaut syndrome
Usual adult dose
Usually started at 0.1 mg/kg twice daily and increased gradually; maximum depends on other medicines and syndrome, up to 0.35 mg/kg twice daily.
Usual dose in children
For children aged 2 years and older, usually started at 0.1 mg/kg twice daily and increased gradually; maximum depends on other medicines and syndrome.
Common side effects
- Reduced appetite and weight loss
- Diarrhea, vomiting, or constipation
- Sleepiness, tiredness, or weakness
- Increased blood pressure
Important warnings
- Can cause heart valve disease or pulmonary arterial hypertension; heart scans are required before and during treatment.
- May cause serious sleepiness or breathing problems, especially with other sedating medicines.
- Monitor weight, appetite, and growth in children.
- Controlled medicine; misuse can cause dependence.
Pregnancy
Human pregnancy information is limited; use only when a clinician judges benefits outweigh risks.
Breastfeeding
It is unknown whether fenfluramine passes into breast milk; breastfeeding is generally not recommended during treatment.
Interactions
- Stiripentol with clobazam can increase fenfluramine exposure; dose reduction may be needed.
- Serotonergic medicines can increase serotonin syndrome risk.
- Sedatives and alcohol can worsen sleepiness and breathing problems.
- Strong CYP1A2 or CYP2D6 inhibitors may increase fenfluramine levels.
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 It may be incomplete or out of date.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.