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Fenfluramine oral

Updated 2 Feb 2023 | Other antiepileptics


Oral formulations of fenfluramine.

Drugs List

  • fenfluramine 2.2mg/ml oral solution sugar-free
  • FINTEPLA 2.2mg/ml oral solution
  • Therapeutic Indications


    Seizures associated with Dravet syndrome

    Treatment of seizures associated with Dravet syndrome as add-on therapy to other anti-epileptic medicines.


    Fenfluramine is prescribed and dispensed according to the controlled access programme.


    Patients who are not taking stiripentol
    Starting dose: 0.1mg/kg twice a day (0.2mg/kg/day)
    After 7 days: 0.2mg/kg twice daily (0.4mg/kg/day) in patients who are tolerating fenfluramine and require a further reduction of seizures.
    After an additional 7 days, the dose can be increased to a maximum of 0.35mg/kg twice daily (0.7mg/kg/day) in patients who are tolerating fenfluramine and require a further reduction of seizures.

    Dose may be increased every 4 days for patients requiring more rapid titration.

    The maximum daily dose of 26mg (13mg twice daily) should not be exceeded.

    Patients who are taking stiripentol
    Starting dose: 0.1mg/kg twice a day (0.2mg/kg/day)
    Maintenance dose after 7 days: 0.2mg/kg twice daily (0.4mg/kg/day) in patients who are tolerating fenfluramine and require a further reduction of seizures.

    Dose may be increased every 4 days for patients requiring more rapid titration.

    The maximum daily dose of 17mg (8.6mg twice daily) should not be exceeded.


    Children over 2 years of age:
    (See Dosage; Adult).


    Children under 2 years
    Within 2 weeks of discontinuing MAOIs
    Moderate hepatic impairment
    Pulmonary hypertension
    Valvular heart disease

    Precautions and Warnings

    Glucose-galactose malabsorption syndrome
    History of anorexia nervosa
    History of bulimia nervosa

    Advise ability to drive/operate machinery may be affected by side effects
    Treatment to be initiated and supervised by a specialist
    Contains glucose
    Contains hydroxybenzoate
    Perform echocardiography before commencing therapy
    May increase seizure frequency
    Monitor patient for weight loss
    Perform echocardiography at 6 monthly intervals during treatment
    Avoid abrupt withdrawal
    To discontinue, reduce dose gradually
    Discontinue if patient develops decreased visual acuity +/or ocular pain
    Advise patient not to take St John's wort concurrently
    Advise that effects are potentiated by CNS depressants (including alcohol)
    Advise patient/carers to report signs of suicide ideation or behaviour

    Prior to initiating treatment, patients must undergo an echocardiogram (echo) to establish a baseline and exclude any pre-existing valvular heart disease or pulmonary hypertension. An echo should be conducted every 6 months for the first 2 years and annually thereafter. If an echo shows pathological valvular changes, an earlier follow-up echo should be considered to evaluate whether the abnormality is persistent. If pathological abnormalities on the echo are observed, it is recommended to evaluate the benefit versus risk of continuing fenfluramine treatment with the prescriber, caregiver, and cardiologist. If treatment is discontinued due to aortic or mitral valvular heart disease, appropriate monitoring and follow-up should be provided in accordance to local guidelines.

    If echo suggests pulmonary arterial hypertension, a repeat echo should be performed as soon as possible and within 3 months to confirm. If echo finding is confirmed suggestive of an increased probability of pulmonary arterial hypertension defined as 'intermediate probability' by the 2015 European Society of Cardiology (ESC) and the European Respiratory Society (ERS) Guidelines, a benefit-risk evaluation of continuation of fenfluramine by the prescriber, carer and cardiologist should be performed. If echo finding, after confirmation, suggests a high probability of pulmonary arterial hypertension, as defined by the 2015 ESC and ERS Guidelines, it is recommended that fenfluramine treatment is discontinued.

    Pregnancy and Lactation


    Fenfluramine is contraindicated during pregnancy.

    The manufacturer does not recommend using fenfluramine during pregnancy.

    There is limited data from the use of fenfluramine during pregnancy. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity in the absence of paternal or maternal toxicity.


    Fenfluramine is contraindicated during breastfeeding.

    The manufacturer advises that the patient either discontinues or abstains from fenfluramine or discontinues breastfeeding taking consideration the benefit of breastfeeding for the neonate and the benefit of the therapy to the women.

    It is unknown whether fenfluramine and/or its metabolites are excreted in human breast milk. Animal studies have shown that fenfluramine/metabolites can be excreted in milk. A risk to the infant cannot be excluded.

    Side Effects

    Behavioural disturbances
    Decreased appetite
    Decreased blood glucose
    Ear infection
    Echocardiogram abnormal (trace regurgitation)
    Glaucoma (closed angle)
    Increased susceptibility to infection
    Status epilepticus
    Suicidal ideation
    Upper respiratory tract infection
    Weight loss


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: July 2021

    Reference Sources

    Summary of Product Characteristics: Fintepla 2.2mg/ml oral solution. Zogenix International Ltd. Revised May 2021.

    NICE Evidence Services Available at: Last accessed: 05 November 2021

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    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

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    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.