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Generic Name: pegvaliase (peg VAL i ase)
Brand Name: Palynziq

Medically reviewed by on Jul 15, 2019 – Written by Cerner Multum

What is pegvaliase?

Pegvaliase is a man-made form of an enzyme that metabolizes phenylalanine.

Pegvaliase is used in adults with phenylketonuria (PKU) to lower phenylalanine blood levels when they are not controlled with other treatment

Pegvaliase is available only from a certified pharmacy under a special program.

Pegvaliase may also be used for purposes not listed in this medication guide.

Important Information

Pegvaliase can cause a serious allergic reaction. You will receive your first dose in a hospital or clinic setting to make sure you do not have an allergic reaction.

Before taking this medicine

Pegvaliase can cause a serious allergic reaction. Your doctor may prescribe an epinephrine injection kit to use in case you have a severe allergic reaction. Keep this injection kit with you at all times.

Tell your doctor if you think you might be unable to give yourself an emergency epinephrine injection.

Follow your doctor's instructions about using pegvaliase if you are pregnant. Control of your phenylalanine levels is very important during pregnancy, and your dose needs may change if your levels get too high or too low.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of pegvaliase on the baby.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

Pegvaliase is not approved for use by anyone younger than 18 years old.

How should I use pegvaliase?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You will receive your first dose in a hospital or clinic setting. You will be watched closely for at least 1 hour to make sure you do not have an allergic reaction.

Pegvaliase is injected under the skin. A healthcare provider may teach you how to properly use the medication by yourself.

You may be given other medications to help prevent allergic reaction. Keep using these medicines for as long as your doctor has prescribed.

You may need to have someone with you when you use this medicine at home, to watch you for signs of an allergic reaction and give the epinephrine injection if needed.

Read and carefully follow any Instructions for Use provided with your medicine. Do not use pegvaliase if you don't understand all instructions for proper use. Ask your doctor or pharmacist if you have questions.

Prepare your injection only when you are ready to give it. Do not use if the medicine has changed colors or has particles in it. Call your pharmacist for new medicine.

Do not shake the prefilled syringe or you may ruin the medicine.

Your care provider will show you where on your body to inject pegvaliase. Use a different place each time you give an injection. Do not inject into the same place two times in a row.

Pegvaliase comes with a Medication Guide and a Warning Card listing symptoms of an allergic reaction. Read this information and learn what symptoms to watch for. Keep the Wallet Card with you at all times.

You will need frequent medical tests.

You will need to follow a special diet while using pegvaliase. Follow all instructions of your doctor or dietitian. Learn about the foods to eat or avoid to help control your condition.

Store this medicine in the refrigerator, do not freeze.

You may store the medicine for up to 30 days at room temperature in its original container, protected from light. Do not put the medicine back into the refrigerator. Throw away any unused medicine after 30 days or after the expiration date on the label has passed.

Each single-use prefilled syringe is for one use only. Throw it away after one use, even if there is still medicine left inside.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using pegvaliase?

Avoid injecting pegvaliase into skin that is red, bruised, hard, tender, injured, or irritated. Do not inject pegvaliase into skin areas with moles, scars, birthmarks, or tattoos.

Pegvaliase side effects

Stop the pegvaliase injection and get emergency medical help if you have signs of an allergic reaction:

  • hives, rash, itching;

  • confusion, dizziness, feeling like you might pass out;

  • nausea, vomiting, diarrhea;

  • loss of bladder or bowel control;

  • fast heartbeats;

  • wheezing, chest tightness, difficult breathing;

  • flushing (warmth, redness, or tingly feeling); or

  • swelling of your face, lips, tongue, or throat.

Common side effects may include:

  • a spreading skin reaction (itching, redness, rash) that could last at least 14 days;

  • headache, joint pain;

  • nausea, vomiting, stomach pain, diarrhea;

  • tiredness; or

  • pain, tenderness, bruising, redness, itching, or swelling where the injection was given.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Pegvaliase dosing information

Usual Adult Dose for Phenylketonuria:

Induction: 2.5 mg subcutaneously once a week for 4 weeks
-Titrate in a step-wise manner as tolerated over at least 5 weeks (described below); additional time may be required prior to each dose escalation based on tolerability
Maintenance dose: 20 mg subcutaneously once a day
Maximum dose: 40 mg subcutaneously once a day

Week 1: 2.5 mg subcutaneously twice a week
Week 2: 10 mg subcutaneously once a week
Week 3: 10 mg subcutaneously twice a week
Week 4: 10 mg subcutaneously four times a week
Week 5: 10 mg subcutaneously once a day

-If, after 24 weeks at 20 mg/day, patient has not achieved either a 20% reduction in blood phenylalanine concentration or a blood phenylalanine concentration of 600 micromol/L or less, consider increasing dose to 40 mg/day.
-If, after 16 weeks at 40 mg/day the patient has not achieved at least a 20% reduction in blood phenylalanine concentration or a blood phenylalanine concentration of 600 micromol/L or less, therapy should be discontinued.

-Administer initial dose under the supervision of a healthcare provider.
-Obtain baseline blood phenylalanine concentration.
-Therapeutic response may not be achieved until titration to an effective maintenance dose is achieved; individualize dose, use lowest effective and tolerated dose.

Use: To reduce blood phenylalanine concentrations in patients with phenylketonuria (PKU) who have uncontrolled blood phenylalanine concentrations greater than 600 micromol/L on existing management.

What other drugs will affect pegvaliase?

Other drugs may affect pegvaliase, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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