Pegvaliase-pqpz Injection
Pegvaliase-pqpz (Palynziq) is an enzyme therapy given by subcutaneous injection to lower blood phenylalanine levels in adults and adolescents with phenylketonuria (PKU) whose phenylalanine remains poorly controlled on other treatments.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Palynziq carries a boxed warning — the FDA's most serious safety alert — for anaphylaxis (a sudden, severe, potentially life-threatening allergic reaction). This reaction has been reported in patients taking Palynziq and can happen at any point during treatment — even after months or years on the medicine. Most reactions occur within an hour of the injection, but delayed reactions up to 48 hours later have also been reported.
Because of this risk: your first dose must be given in a healthcare setting equipped to treat anaphylaxis, and you must be watched for at least 60 minutes. Before self-injecting at home, you and anyone who may be with you must learn to recognize anaphylaxis symptoms and know how to use epinephrine. You must carry epinephrine at all times. Palynziq is only available through a restricted safety program called the Palynziq REMS. Warning signs of anaphylaxis include: throat tightening, difficulty breathing or wheezing, dizziness or fainting, fast heartbeat, face or lip swelling, and severe hives or flushing.
📖 Pegvaliase-pqpz Injection: Patient Information Guide
A plain-language walkthrough of Pegvaliase-pqpz Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Pegvaliase-pqpz is an enzyme therapy used to lower blood phenylalanine levels in people with phenylketonuria (PKU) who aren't adequately controlled on other treatments.
- Palynziq (subcutaneous injection) is approved to reduce blood phenylalanine concentrations in adults and pediatric patients 12 years of age and older with PKU whose blood phenylalanine levels remain greater than 600 micromol/L despite existing management.
⚙️How it works▾
In PKU, the body lacks a working version of the enzyme phenylalanine hydroxylase (PAH), so phenylalanine builds up to toxic levels in the blood. Pegvaliase-pqpz is a different enzyme — a PEGylated phenylalanine ammonia lyase (PAL) — that acts as a substitute. It converts phenylalanine into two harmless byproducts (ammonia and trans-cinnamic acid), reducing the dangerous buildup. The PEG (polyethylene glycol) coating helps the enzyme survive longer in the body and reach effective concentrations.
Because the immune system recognizes the enzyme as foreign, virtually all patients develop antibodies to it. These antibodies can affect how much drug stays in the blood and contribute to allergic-type reactions — which is why careful dose escalation and close monitoring are essential throughout treatment.
💊How it's taken▾
Palynziq is given as a once-daily (or less frequent, during early treatment) subcutaneous injection. Treatment follows a structured three-phase approach: induction (starting at a very low dose once weekly), titration (gradually increasing over at least several weeks), and maintenance (a stable once-daily dose). The dose is adjusted based on blood phenylalanine levels and how well each person tolerates the medicine.
- The first dose must always be given under healthcare provider supervision.
- Blood phenylalanine is checked every 4 weeks until a stable maintenance dose is established, and periodically after that.
- If a dose is missed, take the next dose as scheduled — never double up.
- Dietary protein and phenylalanine intake should be monitored and adjusted throughout treatment by your care team.
🤒Side effects — in detail▾
Most people experience some side effects, especially during the early dose-escalation phase. Common ones include:
- Injection site reactions (redness, pain, swelling, itching, bruising)
- Joint and muscle pain (arthralgia, back pain, pain in the limbs)
- Hypersensitivity reactions (rash, hives, generalized itching)
- Headache
- Nausea, vomiting, abdominal pain, diarrhea
- Fatigue and dizziness
- Cough, sore throat, nasal congestion
- Anxiety
- Hair loss (alopecia) — reported in some patients during maintenance
Side effects tend to be most frequent during the induction and titration phases and generally decrease over time. Serious reactions — including anaphylaxis and significant injection site infections — require immediate medical attention.
⚠️Warnings & precautions▾
- Anaphylaxis (severe allergic reaction): This is the biggest risk. It occurred in about 10% of patients in clinical trials and can happen at any time — even years into treatment. Always carry epinephrine. Know the signs: throat tightening, trouble breathing, fast heartbeat, fainting, severe swelling. Get emergency help immediately if this happens.
- PALYNZIQ REMS program: Because of the anaphylaxis risk, Palynziq is only available through a restricted safety program. Both prescribers and pharmacies must be enrolled. Patients must be educated about the risks before starting.
- Other hypersensitivity reactions: Rashes, hives, and joint pain related to immune reactions occurred in about 72% of patients. Management depends on how severe and how often they occur.
- Serious injection site infections: Abscess, cellulitis, tissue damage, and ulcers have been reported, some requiring hospitalization. Use proper sterile technique; report any signs of infection promptly.
- Hypophenylalaninemia (phenylalanine dropping too low): Phenylalanine is still needed by the body. If levels fall too low, the dose may need to be reduced or dietary intake adjusted. This is especially important during pregnancy.
🔀What it interacts with▾
There is currently one key drug interaction identified for Palynziq to be aware of:
- Other PEGylated medicines (drugs containing polyethylene glycol, such as certain injectable contraceptives like medroxyprogesterone acetate suspension): Because Palynziq causes the body to make antibodies against PEG, using other PEG-containing medications at the same time can trigger serious hypersensitivity reactions, including anaphylaxis. Tell your doctor and pharmacist about every medicine you take, including injections and contraceptives.
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Pregnancy: Uncontrolled phenylalanine during pregnancy is linked to miscarriage, serious birth defects, and intellectual disability in the baby. If you are pregnant or planning to become pregnant, discuss the risks and benefits carefully with your doctor — phenylalanine levels must be tightly monitored throughout pregnancy.
- Breastfeeding: It is not known how much pegvaliase-pqpz passes into human milk or how it affects a breastfed baby. Palynziq may lower phenylalanine levels in breast milk. Discuss breastfeeding with your doctor before starting or continuing Palynziq.
- Age under 12: Palynziq's safety and effectiveness have not been established in children under 12 years of age.
- Epinephrine requirement: You must have epinephrine prescribed and available at all times before starting Palynziq.
- REMS enrollment: You must be enrolled in the Palynziq REMS program before receiving this medicine.
- PEGylated drug use: Tell your doctor if you use any other injectable medicine that contains polyethylene glycol (PEG), as the combination may increase your allergy risk.
📡Pharmacodynamics — effects in the body▾
Palynziq works by breaking down phenylalanine in the blood, and blood phenylalanine levels fall as drug levels increase during treatment. When drug levels in the blood drop — for example, due to immune-related clearance — phenylalanine levels tend to rise again. As a byproduct of the enzyme's action, ammonia and trans-cinnamic acid levels in the blood also increase during treatment, though the long-term significance of these changes has not been fully established.
🔬Pharmacokinetics — how your body processes it▾
After subcutaneous injection, pegvaliase-pqpz reaches peak blood levels in about 8 hours. Drug levels vary considerably from person to person — and even in the same person over time — because each patient's immune response is different; higher antibody levels cause the drug to be cleared from the body faster. The drug's half-life (the time for blood levels to fall by half) averages roughly 47–60 hours during maintenance, but varies widely. During the first 8 weeks of treatment, blood levels are often very low or undetectable. The drug is expected to be broken down into small peptides and amino acids, as enzymes typically are.
📦How to store it▾
Store in refrigerator at 36°F to 46°F (2°C to 8°C) in its original carton to protect from light. Do not freeze or shake. store PALYNZIQ in the original carton at room temperature between 68°F to 77°F (20°C to 25°C) for up to 30 days.
📄 Written from Pegvaliase-pqpz Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Pegvaliase-pqpz Injection — the kind of thing our pharmacy team would talk through with you at the counter.
Why do I have to enroll in a special program just to get this medication? ▾
What does anaphylaxis actually look and feel like, and what should I do if it happens? ▾
The joint pain is really bothering me — is that normal, and will it get better? ▾
I'm a woman of childbearing age. Is it safe to take Palynziq if I want to get pregnant? ▾
I take a birth control shot — is that okay to use with Palynziq? ▾
How long will it take before I start to see my phenylalanine levels go down? ▾
Is Pegvaliase-pqpz Injection available over the counter? ▾
When was Pegvaliase-pqpz Injection first available? ▾
💬 Answers drafted from Pegvaliase-pqpz Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Pegvaliase-pqpz Injection comes
Pegvaliase-pqpz Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Injection
How this form is used
- Palynziq is used subcutaneously to reduce blood phenylalanine concentrations in adults and patients 12 years and older with PKU whose levels remain above 600 micromol/L on existing management
- Palynziq treatment is started at a low once-weekly dose and gradually increased over weeks to a once-daily maintenance dose
- Palynziq is injected under the skin (subcutaneously) into the front of the thigh or abdomen (at least 2 inches from the navel); a caregiver may also use the upper buttocks or back of the upper arms
- Palynziq prefilled syringes are single-use only — inspect for particles or discoloration before use and discard if the solution looks cloudy or unusual
- Rotate Palynziq injection sites with each dose; if more than one injection is needed for a single dose, keep the sites at least 2 inches apart
- Do not inject Palynziq into skin that is red, irritated, infected, scarred, tattooed, or otherwise damaged
📊 Pegvaliase-pqpz Injection across the U.S. market
How Pegvaliase-pqpz Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
📈 How widely Pegvaliase-pqpz Injection is used
A general measure of how commonly Pegvaliase-pqpz Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Pegvaliase-pqpz Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Pegvaliase-pqpz Injection prescribed? Of the 1,596 medications we measure, Pegvaliase-pqpz Injection ranks #1,318 by Medicaid prescriptions — more than 17% of them.
Utilization by Pegvaliase-pqpz Injection product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
1 ML pegvaliase-pqpz 20 MG/ML Prefilled Syringe Most dispensed
Summed across the 2 of 3 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2046379
0.5 ML pegvaliase-pqpz 20 MG/ML Prefilled Syringe
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2046365
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Pegvaliase-pqpz Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 3 of 5 listed Pegvaliase-pqpz Injection NDCs with Medicaid activity.
🔍 Compare Pegvaliase-pqpz Injection products
A representative set of FDA-listed product records for Pegvaliase-pqpz Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 2.5 mg/0.5 mL | Subcutaneous | BioMarin Pharmaceutical Inc. × 3 listings | BLA | View NDC → |
| 5 mg/mL | — | BioMarin Pharmaceutical Inc. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 10 mg/0.5 mL | Subcutaneous | BioMarin Pharmaceutical Inc. × 3 listings | BLA | View NDC → |
| 20 mg/mL | — | BioMarin Pharmaceutical Inc. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 20 mg/mL | Subcutaneous | BioMarin Pharmaceutical Inc. × 3 listings | BLA | View NDC → |
Showing 11 of 11 products — FDA National Drug Code Directory. See every product, package size and price: browse all 11 Pegvaliase-pqpz Injection NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Pegvaliase-pqpz Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Pegvaliase-pqpz Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Pegvaliase-pqpz Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2046360 1 dose form · 3 strengths
-
Dose form (SCDF) Prefilled Syringe RxCUI 2046364No current FDA listingClinical drug / strength (SCD) 0.5 ML pegvaliase-pqpz 20 MG/MLRxCUI 20463650.5 ML pegvaliase-pqpz 5 MG/MLRxCUI 20463741 ML pegvaliase-pqpz 20 MG/MLRxCUI 2046379
Look up RxCUI 2046360 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Pegvaliase-pqpz Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Pegvaliase-pqpz Injection belongs to the Phenylalanine Metabolizing Enzyme class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. BioMarin Pharmaceutical Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.