Difelikefalin Injection
Difelikefalin injection (Korsuva) is used to treat moderate-to-severe itching caused by chronic kidney disease in adults on hemodialysis.
🧬 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 →
📖 Difelikefalin Injection: Patient Information Guide
A plain-language walkthrough of Difelikefalin 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▾
Difelikefalin injection is approved for one condition, attributed to the brand Korsuva:
- Korsuva is indicated for the treatment of moderate-to-severe pruritus (chronic, severe itching) associated with chronic kidney disease (CKD-aP) in adults undergoing hemodialysis.
- Korsuva is not recommended for patients on peritoneal dialysis, as it has not been studied in this group.
⚙️How it works▾
Difelikefalin is a kappa opioid receptor (KOR) agonist — meaning it activates a specific type of receptor found throughout the nervous system. These kappa opioid receptors are thought to play a role in the perception of itch. By binding to and switching on these receptors, difelikefalin may help reduce the intense itching that can come with chronic kidney disease. The exact relationship between this receptor activation and the relief of itching is not yet fully understood.
💊How it's taken▾
Korsuva is given as an intravenous (IV) injection into the venous line of the dialysis circuit — it is not a pill or a home injection. It is administered at the end of every hemodialysis session, after blood is no longer passing through the dialyzer.
- The injection may be given during or after the rinse-back portion of dialysis.
- If given after rinse back, the line should be flushed with at least 10 mL of normal saline afterward.
- If a scheduled dialysis session is missed, simply resume Korsuva at the end of the next session.
🤒Side effects — in detail▾
The most commonly reported side effects with Korsuva include:
- Diarrhea
- Dizziness (most often in the first 3 weeks; usually transient)
- Nausea
- Gait disturbances, including falls (trouble walking or keeping balance)
- Hyperkalemia (high potassium levels in the blood)
- Headache
- Somnolence (drowsiness; more common in adults 65 and older)
- Mental status changes, including confusion
Contact your care team right away if confusion, significant dizziness, extreme drowsiness, or difficulty walking become serious or don't improve, or if you fall.
⚠️Warnings & precautions▾
- Dizziness, drowsiness, mental status changes, and gait problems (including falls) have occurred in patients taking Korsuva. These effects appeared most often within the first 3 weeks and often improved over time. Older adults (65+) are more likely to experience drowsiness.
- Do not drive or operate heavy machinery until you know how Korsuva affects your alertness and coordination.
- Caution with sedating medicines: Using opioid pain relievers, sedating antihistamines, or other central nervous system depressants at the same time as Korsuva can increase the risk of these side effects.
- High potassium (hyperkalemia): The incidence was higher in patients taking Korsuva, and was notably higher in patients also taking opioids. Your care team should monitor your potassium levels.
🔀What it interacts with▾
No formal drug interaction clinical studies have been conducted with difelikefalin. However, based on its effects and lab studies, the following should be used with caution:
- Opioid pain medicines: May worsen drowsiness, confusion, and dizziness, and increase the risk of high potassium levels when combined with Korsuva.
- Centrally-acting depressant medications (medicines that slow or calm the brain and nervous system): May amplify Korsuva's sedating side effects.
- Sedating antihistamines (allergy or sleep medicines that cause drowsiness): May increase the likelihood of dizziness, drowsiness, and other nervous system effects.
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▾
- Severe liver disease: Korsuva has not been studied in patients with severe hepatic (liver) impairment and is not recommended for this group.
- Peritoneal dialysis: Korsuva is not recommended for patients on peritoneal dialysis — it has only been studied in hemodialysis patients.
- Pregnancy: There are limited human data on Korsuva use during pregnancy. Discuss the risks and benefits with your doctor.
- Breastfeeding: It is unknown whether difelikefalin passes into human breast milk. Discuss with your doctor before breastfeeding while on this medication.
- Children: The safety and effectiveness of Korsuva in pediatric patients have not been established.
- Older adults (65+): More likely to experience drowsiness with Korsuva. No dose adjustment is needed, but closer monitoring is warranted.
- Mild-to-moderate liver disease: No dose adjustment is needed based on available data.
🚑If you take too much▾
In clinical studies, doses much higher than the recommended amount caused increased side effects including dizziness, drowsiness, confusion, tingling or numbness (paresthesia), fatigue, high blood pressure, and vomiting. If an overdose occurs, medical attention should be provided based on the patient's symptoms and clinical condition. Hemodialysis can effectively remove a large portion of difelikefalin from the blood.
📡Pharmacodynamics — effects in the body▾
The precise relationship between difelikefalin's blood levels and its therapeutic effect on itch is not yet fully characterized. At doses much higher than recommended, difelikefalin does not cause clinically meaningful changes to the heart's electrical rhythm (specifically, it does not prolong the QTc interval, a marker of heart rhythm risk).
🔬Pharmacokinetics — how your body processes it▾
After intravenous administration, difelikefalin reaches a steady level in the blood after just the second dose. It has a half-life (the time it takes for the body to reduce the drug level by half) of roughly 23 to 31 hours in hemodialysis patients before their dialysis session. The drug is not broken down by the liver's main enzyme system (CYP450 enzymes), and it does not significantly interfere with common drug-processing proteins, making major drug interactions through these pathways unlikely. Hemodialysis itself removes about 70–80% of difelikefalin from the blood, and the drug is undetectable after two dialysis cycles — which is why it is always given at the end of a session, not before.
📦How to store it▾
Store vials at 20°C to 25°C (68°F to 77°F), excursions permitted to 15°C to 30°C (59°F to 86°F) . Do not freeze. stored at ambient temperature 20°C to 25°C (68°F to 77°F) until dosing .
📄 Written from Difelikefalin 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 Difelikefalin Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is Korsuva for? My doctor said it's for itching from my kidney disease. ▾
How is it given? I hate needles — do I have to inject myself at home? ▾
What side effects should I expect, and which ones should make me call someone? ▾
Is it safe for me to drive after my dialysis sessions if I'm on Korsuva? ▾
I take pain medicine and an antihistamine for allergies. Is that a problem with Korsuva? ▾
I'm 70 years old. Is this medication safe for someone my age? ▾
Is Difelikefalin Injection available over the counter? ▾
When was Difelikefalin Injection first available? ▾
Who makes Difelikefalin Injection? ▾
💬 Answers drafted from Difelikefalin 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 Difelikefalin Injection comes
Difelikefalin 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
- Korsuva is used to treat moderate-to-severe itching (pruritus) associated with chronic kidney disease in adults on hemodialysis
- Korsuva is not recommended for use in patients on peritoneal dialysis
- Korsuva is administered as an intravenous bolus injection into the venous line of the dialysis circuit at the end of each hemodialysis session
- Korsuva must not be mixed or diluted before administration — inspect it first and do not use if the solution is cloudy or contains particles
- Korsuva must be administered after blood is no longer circulating through the dialyzer; if given after rinse back, follow with at least 10 mL of normal saline flush
- Korsuva must be used within 4 hours of syringe preparation; discard any unused product
📊 Difelikefalin Injection across the U.S. market
How Difelikefalin 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.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Difelikefalin Injection is used
A general measure of how commonly Difelikefalin 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 Difelikefalin 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 Difelikefalin Injection prescribed? Of the 1,596 medications we measure, Difelikefalin Injection ranks #1,568 by Medicaid prescriptions — more than 2% of them.
Utilization by Difelikefalin 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.
1.3 ML difelikefalin 0.05 MG/ML Injection
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2569094
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 Difelikefalin 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 1 of 2 listed Difelikefalin Injection NDCs with Medicaid activity.
🔍 Compare Difelikefalin Injection products
A representative set of FDA-listed product records for Difelikefalin 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 | ||||
| 50 mcg/mL | — | Patheon Italia S.p.A. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 50 mcg/mL | Intravenous | Vifor (International), Inc. | NDA | View NDC → |
| 50 mcg/mL | Intravenous | Vifor (International) Inc. | NDA | View NDC → |
Showing 3 of 3 products — FDA National Drug Code Directory. See every product, package size and price: browse all 3 Difelikefalin 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 Difelikefalin 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 Difelikefalin 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 Difelikefalin 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 2569089 1 dose form · 1 strength
-
Dose form (SCDF) Injection RxCUI 2569093In current FDA listingsClinical drug / strength (SCD) 1.3 ML difelikefalin 0.05 MG/MLRxCUI 2569094
Look up RxCUI 2569089 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 Difelikefalin 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
Difelikefalin Injection belongs to the Kappa Opioid Receptor Agonist 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. Vifor (International) 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.