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Alglucosidase alpha

Updated 2 Feb 2023 | Pompe disease

Drugs List

  • alglucosidase alfa 50mg powder for concentrate for solution for infusion
  • MYOZYME 50mg powder for concentrate for solution for infusion
  • Dosage

    The recommended dosage regimen of alglucosidase alfa for all patients is 20 mg/kg of body weight administered once every 2 weeks as an intravenous infusion ( see Administration for details )

    The safety and efficacy of alglucosidase alfa have been primarily evaluated in children ranging from infancy to adolescence.

    Patients with Renal Impairment

    Studies in patients with renal impairment have not been performed.

    Patients with Hepatic Impairment

    Studies in patients with hepatic impairment have not been performed.

    Additional Dosage Information

    Treatment should be supervised by a physician experienced in the management of Pompe disease or other inherited metabolic or neuromuscular diseases.


    For intravenous infusion after reconstitution and dilution.

    Infusions should be administered incrementally as soon after preparation as possible. It is recommended that the infusion begin at an initial rate of 1mg/kg/hr and be gradually increased by 2 mg/kg/hr every 30 minutes if there are no signs of infusion associated reactions until a maximum rate of 7mg/kg/hr is reached.


    The required number of vials should be at room temperature before reconstitution and dilution takes place.

    The vials are intended for use on a single occasion and any unused material should be discarded.


    Each vial of alglucosidase alfa should be reconstituted with 10.3ml water for injections. Add the water for injections carefully by slow drop-wise addition down the side of the vial. Tilt and roll each vial gently, ensuring that it is not inverted, swirled or shaken. The reconstituted solution in the vial contains 5mg alglucosidase alfa per ml.

    Dilution is recommended immediately after reconstitution using 9 mg/ml (0.9%) sodium chloride injection. Slowly withdraw the reconstituted solution from each vial until the volume of the patient's dose is obtained. The recommended final concentration of alglucosidase in the infusion bags ranges from 0.5 mg/ml to 4 mg/ml. Once the airspace has been removed from within the infusion bag, remove an equal volume of the sodium chloride that will be replaced with the reconstituted alglucosidase alfa. Inject the reconstituted alglucosidase alfa directly into the sodium chloride solution and gently invert the bag to mix.

    Particles may form in the reconstituted solution and the final bag. A 0.2 micron in-line low protein-binding filter should be used during administration. This does not result in loss of protein or activity.


    In the absence of studies, alglucosidase alfa should not be mixed with other medicinal products in the same infusion.


    Breast feeding (see 'Lacation' section)

    Precautions and Warnings

    Treatment should be supervised by a physician experienced in the management of Pompe disease or other inherited metabolic or neuromuscular diseases.

    Pregnancy (see ' Pregnancy' section)

    Renal Impairment - No data available

    Hepatic Impairment - No data available

    It is expected that the majority of patients will develop IgG antibodies to alglucosidase alfa, typically within 3 months. Infantile-onset patients treated with a higher dose (40mg/kg) tended to develop higher titres of IgG antibodies. There does not seem to be a correlation between the onset of IARs and the time of IgG antibody formation. Antibody titres should be monitored regularly.

    Compromised cardiac and respiratory function may be evident in patients with advanced Pompe disease. These patients should be monitored closely as they may be more predisposed to a higher risk of severe complications from Infusion Associated Reactions (IARs).

    Use with caution in patients who have previously experienced IARs. IARs may occur at any time during the infusion or up to 2 hours after. They are more likely with higher infusion rates. Mild and transient effects may not require medical treatment or discontinuation of the infusion. Often reduction of the infusion rate, temporary interruption of the infusion or pre-treatment with oral antihistamines and/or antipyretics and/or corticosteroids has effectively managed most reactions.

    Patients with an acute illness (e.g. pneumonia, sepsis) at the time of infusion appear to be at greater risk for IARs. Patients should be closely monitored and all cases of IARs, delayed reactions and possible immunological reactions should be reported.

    Severe skin reactions including ulcerating and necrotising lesions have been reported and are possibly immune-related. Periodic urinalysis should be performed in patients with high IgG antibody titres. During treatment, monitor patients for signs or symptoms of systemic immune-complex mediated reactions involving skin or other organs. If such reactions occur, discontinue treatment and institute appropriate therapy. Some patients have been successfully restarted on alglucosidase alfa after such reactions under close medical supervision.

    Discontinue the infusion immediately in the event of severe allergic or anaphylactic type reaction and initiate appropriate medical treatment in accordance with the current medical standards for emergency treatment.

    The benefits of alglucosidase alfa in patients with late-onset Pompe disease have not been established.

    Pregnancy and Lactation


    Alglucosidase alpha should be used with caution during pregnancy. Animal studies have shown reproductive toxicity.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password at ( ) or if this is unavailable at the backup site ( ).


    Alglucosidase alfa may be excreted in milk. There are no data available on the effects in neonates exposed to alglucosidase alfa via breast milk.

    The manufacturers recommend that the patient should stop breastfeeding when alglucosidase alfa is used.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Maculopapular rash
    Rash macular
    Rash papular
    Increased blood pressure
    Oxygen saturation decreased
    Hot and flushed skin
    Livedo reticularis
    Periorbital oedema
    Anaphylactic reaction
    Face oedema
    Cardiac arrest
    Chest pain
    Pharyngeal oedema
    Throat tightness
    Infusion site pain
    Infusion site reaction
    Increased body temperature
    Increased heart rate
    Angioneurotic oedema
    Antibody formation
    Cold extremities
    Respiratory distress
    Local swelling
    Abdominal pain
    Respiratory arrest
    Peripheral oedema
    Nephrotic syndrome
    Muscle spasm
    Muscle twitching


    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 ( ).

    Shelf Life and Storage

    Store in a refrigerator at 2-8 degrees C.

    After dilution the product should be used immediately. If it is not used immediately the chemical and physical stability of the product has been demonstrated for 24 hours at 2 to 8 degrees C when protected from light. This would however, be the responsibility of the user.

    Reference Sources

    British National Formulary, 62nd Edition (2011) Pharmaceutical Press, London.

    BNF for Children (2011-2012) Pharmaceutical Press, London.

    Summary of Product Characteristics: Myozyme 50mg, powder for concentrate for solution for infusion. Genzyme Therapeutics. Revised November 2011

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