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Enfuvirtide parenteral

Updated 2 Feb 2023 | Other antiretrovirals


Parenteral formulations of enfuvirtide.

Drugs List

  • enfuvirtide 108mg powder for solution for injection
  • FUZEON 108mg powder for solution for injection
  • Therapeutic Indications


    HIV infection-combined with other antiretrovirals

    Treatment of HIV-1 infection in combination with other antiretroviral medicines in patients who have failed on previous regimens containing at least one product from each of the following antiretroviral classes: protease inhibitors, non-nucleoside reverse transcriptase inhibitors and nucleoside reverse transcriptase inhibitors, or who have not tolerated previous antiretroviral regimens.

    Before treatment, consider carefully the treatment history for each patient and the patterns of mutations associated with different medicinal products. Resistance testing may be appropriate.


    Advise patients on the correct method of reconstituting and administrating the injection before they begin to self-inject.


    90mg administered subcutaneously, twice a day into the upper arm, anterior thigh or abdomen.


    Children 16 to 18 years
    90mg administered subcutaneously, twice a day into the upper arm, anterior thigh or abdomen.

    Children aged 6 to 16 years
    Experience is limited, the following dosing schedule has been used in clinical trials:
    Bodyweight 42.6kg or more: 90mg twice a day.
    Bodyweight 38.1kg to 42.5kg: 81mg twice a day.
    Bodyweight 33.6kg to 38kg: 72mg twice a day.
    Bodyweight 29.1kg to 33.5kg: 63mg twice a day.
    Bodyweight 24.6kg to 29kg: 54mg twice a day.
    Bodyweight 20.1kg to 24.5kg: 45mg twice a day.
    Bodyweight 15.6kg to 20kg: 36mg twice a day.
    Bodyweight 11kg to 15.5kg: 27mg twice a day.

    Additional Dosage Information

    In case an enfuvirtide dose is missed, patients should be instructed to administer the dose as soon as possible. However, if it is less than 6 hours before the next regular dose, the missed dose should be skipped.


    To be administered by subcutaneous injection only into upper arm, anterior thigh or abdomen.

    The injection site should be rotated.


    Children under 6 years

    Precautions and Warnings

    Hepatic impairment
    Hepatitis B
    Hepatitis C
    Moderate renal impairment

    Treatment does not prevent risk of transmission of HIV
    Advise ability to drive/operate machinery may be affected by side effects
    Must be used in combination with other antiretrovirals
    Treatment should be initiated by doctor experienced in HIV management
    Discard any unused portion
    For single use only
    Never rechallenge treatment after a hypersensitivity reaction
    Warm to room temperature prior to use
    Autoimmune disorders can occur many months after initiation of treatment
    Advise patient to seek medical advice if joint aches or pain occur
    Advise patient to seek medical advice if movement becomes difficult
    Advise patient to stop therapy & contact Dr if hypersensitivity signs occur
    Inflammatory symptoms should be evaluated and treated appropriately
    May lead to false positive HIV test result in non-infected individuals
    Risk of developing opportunistic infections

    Patients should be informed that treatment does not prevent the transmission of HIV via blood contamination or sexual contact and appropriate precautions should still be used.

    In clinical trials increased incidence of certain bacterial infections especially pneumonia has been seen in patients treated with enfuvirtide. However, it has not been confirmed by subsequent epidemiological data.

    Hypersensitivity to enfuvirtide has been seen to manifest as rash, fever, nausea and vomiting, chills, rigors, low blood pressure and elevated serum liver transaminases in various combinations, and possibly primary immune complex reaction, respiratory distress and glomerulonephritis. Patients showing symptoms of a systemic hypersensitivity reaction should discontinue therapy with enfuvirtide immediately and seek medical attention.

    Hypersensitivity reactions have recurred on rechallenge so therapy should not be restarted following systemic signs and symptoms of such a reaction.

    Treatment in patients suffering from underlying hepatic disorders has not been fully studied.Patients with chronic hepatitis B or C undergoing antiretroviral therapy are at an increased risk of severe and possibly fatal hepatic adverse effects.
    Patients in phase III trials suffering from hepatitis B or C did not experience an increase in hepatic related adverse events. If a patient is also receiving antiviral treatment for hepatitis B/C the relevant product literature should be consulted for these products.

    Enfuvirtide therapy in non-HIV-1 infected individuals may result in induced anti-enfuvirtide antibodies which react with HIV gp41. This may lead to a false positive HIV test with the anti-HIV ELISA test.

    When combination antiretroviral therapy is initiated in HIV-infected patients with severe immune deficiency, an inflammatory reaction to asymptomatic or residual opportunist pathogens may arise. This can lead to the aggravation of symptoms or other serious clinical conditions such as cytomegalovirus retinitis, mycobacterial infections or Pneumocystis carinii pneumonia. These reactions are usually observed within the first few weeks or months after treatment initiation. Any inflammatory symptoms should be evaluated and treated appropriately.

    Cases of osteonecrosis have been reported, particularly in patients with advanced HIV disease and/or long term exposure to combination antiretroviral therapy. The aetiology of this condition is thought to be due to several factors including corticosteroid use, alcohol consumption, severe immunosuppression, higher body mass index. Patients should be advised to seek medical advice if they experience joint aches or pains, joint stiffness or difficulty in movement.

    Pregnancy and Lactation


    Enfuvirtide should be used with caution during pregnancy.

    The manufacturer recommends that enfuvirtide should be used in pregnancy only if the potential benefits justifies the potential risk to the foetus.

    Animal studies have not shown teratogenic effects. Reports suggest that enfuvirtide does not cross the placenta due to the high molecular weight and protein binding of enfuvirtide.


    Enfuvirtide is contraindicated during breastfeeding.

    The manufacturer does not recommend breastfeeding whilst taking enfuvirtide because of the potential for HIV transmission and any potential undesirable effects in breastfed infants.

    The presence of enfuvirtide in human breast milk is unknown but due to its large molecular weight and protein binding, transfer may be inhibited.

    The effects of breastfeeding on a nursing infant are unknown.

    Side Effects

    Abscess formation (injection site)
    Attention disturbances
    Autoimmune hepatitis
    Cellulitis (injection site)
    Creatine phosphokinase increased
    Decrease in haemoglobin
    Decreased appetite
    Diabetes mellitus
    Dry skin
    Ear infection
    Ecchymosis (injection site)
    Erythema at injection site
    Gastroesophageal reflux disease
    Graves' disease
    Hypersensitivity reactions
    Immune disorder
    Immune Reactivation/Reconstitution Syndrome
    Increase in ALT level
    Increase in serum transaminases
    Induration (injection site)
    Influenza-like syndrome
    Local infection at injection site
    Local pain (injection site)
    Local reaction at injection site
    Nasal congestion
    Nodules (injection site)
    Peripheral neuropathy
    Renal calculus
    Respiratory distress syndrome
    Skin papilloma
    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: August 2022

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Summary of Product Characteristics: Fuzeon 90mg/ml powder and solvent for solution for injection. Roche Products Limited. Revised January 2021.

    NICE Evidence Services Available at: Last accessed: 11 August 2022

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