Pegloticase Injection
Pegloticase injection (Krystexxa) is an intravenous enzyme therapy used to treat chronic gout that has not responded to standard medications.
🧬 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 ▾
Krystexxa carries serious boxed warnings about life-threatening allergic reactions and a dangerous blood condition in certain patients.
Severe allergic reactions (anaphylaxis) and infusion reactions can occur with any Krystexxa infusion — even the first one. These usually happen within 2 hours but can also occur later. Signs include wheezing, swelling of the mouth or tongue, severe rash, or a sudden drop in blood pressure. Because of this risk, Krystexxa must only be given in a medical setting by providers ready to treat these reactions. You will receive antihistamines and corticosteroids before each infusion to reduce the risk. Your uric acid level will be checked before every infusion; if it rises above the target level (especially on two visits in a row), treatment will be stopped because that significantly raises the reaction risk.
Patients with G6PD deficiency must not use Krystexxa. G6PD deficiency is a genetic enzyme disorder more common in people of African, Mediterranean, and Southern Asian descent. In people with this condition, Krystexxa can cause hemolysis (rupture of red blood cells) and methemoglobinemia (a condition where blood can't carry oxygen properly) — both potentially life-threatening. All at-risk patients should be screened before starting treatment.
📖 Pegloticase Injection: Patient Information Guide
A plain-language walkthrough of Pegloticase 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▾
Krystexxa (pegloticase) injection is approved for one primary use in adults:
- Chronic gout refractory to conventional therapy — for adults whose gout symptoms and uric acid levels remain uncontrolled despite maximum doses of standard medicines (such as xanthine oxidase inhibitors), or for whom those medicines are contraindicated
- Krystexxa is not recommended for asymptomatic hyperuricemia (high uric acid with no symptoms)
⚙️How it works▾
Uric acid builds up in the blood when the body produces more than it can eliminate, leading to painful crystal deposits in joints — this is gout. Krystexxa contains a lab-engineered enzyme called pegloticase, a form of uricase that the human body normally doesn't produce. This enzyme converts uric acid into a harmless, water-soluble compound called allantoin, which the kidneys then easily excrete. The result is a rapid and significant drop in blood uric acid levels.
Because Krystexxa is a foreign protein, the immune system can develop antibodies against it over time, which may reduce how well it works and raise the risk of reactions. Co-administering methotrexate reduces antibody formation and helps Krystexxa remain effective longer.
💊How it's taken▾
Krystexxa is given as an intravenous infusion in a healthcare facility, typically every two weeks. It is most often co-administered with weekly oral methotrexate (plus folic acid or folinic acid), which should be started at least 4 weeks before the first Krystexxa infusion. Krystexxa may be used alone when methotrexate is not appropriate for a patient.
- Each infusion takes at least 120 minutes — it must never be given as a rapid injection
- Pre-medications (an antihistamine and a corticosteroid) are given before every infusion
- Uric acid levels are checked before each infusion to confirm the treatment is still working safely
- All other oral uric-acid-lowering medicines must be stopped before starting and kept stopped during treatment
🤒Side effects — in detail▾
The most common side effects reported with Krystexxa include:
- Gout flares — very common, especially in the first 3 months as uric acid crystals dissolve
- Infusion reactions — hives, chest discomfort, flushing, itching, or shortness of breath during or after the infusion
- Nausea and vomiting
- Joint pain (arthralgia)
- Bruising or skin discoloration
- Constipation
- Fatigue
- Cold symptoms (nasopharyngitis)
Seek emergency care immediately for signs of a severe allergic reaction (anaphylaxis) — wheezing, mouth/tongue swelling, dizziness, or a sudden drop in blood pressure. These can be life-threatening and require immediate treatment.
⚠️Warnings & precautions▾
- Anaphylaxis: A severe, potentially life-threatening allergic reaction can happen with any infusion, including the first. It usually occurs within 2 hours but delayed reactions are also possible. Every infusion must be in a medical setting with emergency support ready.
- Infusion reactions: Milder reactions (hives, chest tightness, flushing) are common; the infusion may be slowed or temporarily stopped if one occurs. Risk is highest when uric acid levels are rising, signaling the drug may be losing effect.
- G6PD deficiency: Krystexxa is absolutely contraindicated in patients with G6PD deficiency — it can cause dangerous red blood cell destruction (hemolysis) and methemoglobinemia. Screening is required before starting.
- Gout flares: Flares often increase early in treatment as uric acid shifts out of tissues. Preventive medicines (NSAIDs or colchicine) are recommended for at least the first 6 months.
- Congestive heart failure: Cases of worsening heart failure have been reported. Use with caution and close monitoring in patients with this condition.
- Re-treatment risk: Restarting Krystexxa after a gap of more than 4 weeks may increase the risk of reactions due to antibody buildup — extra monitoring is required.
🔀What it interacts with▾
Tell your doctor and pharmacist about all medicines you take before starting Krystexxa — a few interactions matter significantly:
- Methotrexate: Intentionally co-prescribed alongside Krystexxa — it reduces the body's antibody response to the drug, keeping it effective longer and increasing its concentration in the blood
- Other PEGylated (polyethylene glycol-containing) medicines: Antibodies your body makes against Krystexxa target the PEG coating and may potentially affect other PEG-containing drugs — inform your doctor of all biologics or specialty medicines you use
- Oral urate-lowering agents (e.g., allopurinol, febuxostat): Must be stopped before starting Krystexxa and not restarted while on it — continuing them can mask a rise in uric acid that would otherwise signal increased reaction risk
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▾
- G6PD deficiency: Must be ruled out before starting — Krystexxa is contraindicated; screening is especially important for people of African, Mediterranean, or Southern Asian ancestry
- Prior serious allergic reaction to Krystexxa: If you have had anaphylaxis or a serious hypersensitivity reaction to Krystexxa or its components, you cannot use it again
- Congestive heart failure: Tell your doctor — Krystexxa has been associated with worsening heart failure and requires careful monitoring
- Pregnancy: No adequate human studies exist; animal studies showed reduced fetal weight at high doses — discuss risks and benefits with your doctor
- Breastfeeding: It is unknown whether Krystexxa passes into breast milk — avoid breastfeeding unless your doctor determines the benefit to you clearly outweighs the unknown risk to your infant
- Children under 18: Safety and effectiveness have not been established; Krystexxa is not approved for pediatric use
- Older adults (65+): No dose adjustment needed, but individual sensitivity cannot be fully ruled out — monitoring is still important
- Kidney or liver impairment: No dose adjustment is required for kidney disease; formal studies in liver impairment have not been conducted
🚑If you take too much▾
No cases of overdose with Krystexxa have been reported. The highest single intravenous dose studied was 12 mg. If an overdose is suspected, medical staff will monitor the patient and provide general supportive care — there is no specific antidote.
📡Pharmacodynamics — effects in the body▾
Within roughly 24 hours of the first Krystexxa infusion, blood uric acid levels drop dramatically — in clinical trials, average levels fell to around 0.7 mg/dL, compared to 8.2 mg/dL in patients who received placebo. Uric acid is kept below the critical solubility threshold of 6 mg/dL (the level above which crystals form) for an extended period after each infusion. The degree and duration of uric acid suppression are linked to the dose given and to the body's antibody response to the drug.
🔬Pharmacokinetics — how your body processes it▾
Pegloticase levels in the blood are measured indirectly by tracking the enzyme's activity. After an IV infusion, peak blood concentrations rise in proportion to the dose. Factors like age, sex, body weight, and kidney function do not meaningfully affect how the drug is processed. However, body surface area and — importantly — anti-pegloticase antibodies do influence drug levels. When Krystexxa is given alongside methotrexate, antibody levels are lower and pegloticase concentrations in the blood are higher, meaning the drug stays active longer.
📦How to store it▾
stored in the carton and maintained at all times under refrigeration between 2°C to 8°C (36°F to 46°F). Protect from light.
📄 Written from Pegloticase 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 →
Supplements & herbs that interact with Pegloticase Injection
1 supplement and herbal product has documented interactions with Pegloticase Injection in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Pegloticase Injection — the kind of thing our pharmacy team would talk through with you at the counter.
Why is my doctor adding methotrexate to my Krystexxa treatment? I thought methotrexate was for arthritis. ▾
What should I watch for during or after my Krystexxa infusion? ▾
My gout seems to be flaring more since I started Krystexxa. Is that normal? ▾
Is there anyone who absolutely cannot take Krystexxa? ▾
I stopped Krystexxa for a couple of months. Can I just restart it? ▾
Can I keep taking my allopurinol or febuxostat while I'm on Krystexxa? ▾
Is Pegloticase Injection available over the counter? ▾
When was Pegloticase Injection first available? ▾
💬 Answers drafted from Pegloticase 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 Pegloticase Injection comes
Pegloticase 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
- Krystexxa IV infusion is used to treat chronic gout in adults who have not responded to or cannot tolerate standard uric-acid-lowering therapies
- Krystexxa is not intended for treatment of high uric acid without gout symptoms
- Krystexxa is given as a slow intravenous infusion (over at least 120 minutes) every two weeks in a healthcare setting — never as a rapid IV push or bolus
- Krystexxa is available as a Ready-to-Use single-dose vial (hung and infused directly) or a To-be-Diluted single-dose vial (mixed into a sodium chloride bag before infusion) — preparation steps differ between the two and should be handled by healthcare staff
- Krystexxa is typically co-administered with weekly oral methotrexate (plus folic acid supplementation started at least 4 weeks before the first infusion) to improve how well it works; Krystexxa alone may be used when methotrexate is not appropriate
- All other oral uric-acid-lowering medicines should be stopped before starting Krystexxa and not restarted during treatment
📊 Pegloticase Injection across the U.S. market
How Pegloticase 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 Pegloticase Injection is used
A general measure of how commonly Pegloticase 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 Pegloticase 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 Pegloticase Injection prescribed? Of the 1,596 medications we measure, Pegloticase Injection ranks #1,128 by Medicaid prescriptions — more than 29% of them.
Utilization by Pegloticase 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 pegloticase 8 MG/ML Injection Most dispensed
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1011653
50 ML pegloticase 0.16 MG/ML Injection
Summed across the 1 of 1 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2723378
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 Pegloticase 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 2 of 2 listed Pegloticase Injection NDCs with Medicaid activity.
🔍 Compare Pegloticase Injection products
A representative set of FDA-listed product records for Pegloticase 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 | ||||
| 8 mg/50 mL | Intravenous | Horizon Therapeutics USA, Inc. × 3 listings | BLA | View NDC → |
| 8 mg/mL | Intravenous | Horizon Therapeutics USA, Inc. × 5 listings | BLA | View NDC → |
Showing 8 of 8 products — FDA National Drug Code Directory. See every product, package size and price: browse all 8 Pegloticase 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 Pegloticase 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 Pegloticase 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 Pegloticase 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 1011650 1 dose form · 2 strengths
-
Dose form (SCDF) Injection RxCUI 1811408In current FDA listingsClinical drug / strength (SCD) 1 ML pegloticase 8 MG/MLRxCUI 101165350 ML pegloticase 0.16 MG/MLRxCUI 2723378
Look up RxCUI 1011650 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 Pegloticase 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
Pegloticase Injection belongs to the Uric Acid-specific 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. Horizon Therapeutics USA, 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.