At a glance
| Approved product | Korsuva |
|---|---|
| Target | Kappa-opioid receptor |
| Population | Adults receiving hemodialysis |
| Clinical outcome | Itch severity and itch-related quality of life |
| Safety focus | Dizziness, somnolence, mental-status and gait changes |
Overview
Chronic kidney disease-associated pruritus can impair sleep and quality of life. Difelikefalin was developed to address that symptom in a defined dialysis population, using a peptide designed to have limited central nervous system penetration. It is marketed in the United States as Korsuva. The word opioid describes its receptor family, but the clinical role differs from conventional mu-opioid pain medicines. Equally, describing a compound as peripherally restricted does not mean neurologic symptoms are impossible. Evidence and safety need to be read from the actual clinical program, with special attention to the health and medication burden of people receiving dialysis.
How it works
Difelikefalin selectively activates kappa-opioid receptors involved in modulation of itch. Its structure is intended to favor peripheral action, distinguishing it from broadly acting centrally penetrant opioids. The exact contribution of peripheral neuronal and immune pathways to clinical benefit is still more complex than a single switch. A targeted mechanism supports the rationale but does not eliminate the need to assess dizziness, sedation, and function.
The KALM-1 trial
KALM-1 randomized 378 adults receiving hemodialysis with moderate-to-severe itch. Over 12 weeks, more participants receiving difelikefalin achieved a clinically specified reduction in itch scores than those receiving placebo, and itch-related quality of life improved. These results directly support the dialysis indication, but do not establish treatment of eczema, allergy, or every other pruritic disorder.
Supporting sources [2]
Peripheral action is not absence of nervous-system effects
The label reports dizziness, somnolence, altered mental status, and gait disturbances including falls. Concomitant sedating medicines can increase concern. Diarrhea and nausea also occur. These effects deserve attention in a population that may already have substantial comorbidity and vulnerability to falls or cognitive changes.
Supporting sources [1]
Why the dialysis context matters
Korsuva’s approved administration is integrated with hemodialysis care. Findings cannot automatically be transferred to oral investigational formulations, people who are not on dialysis, or unrelated itch mechanisms. Broader research on the molecule must be evaluated separately from the exact product, dialysis population, and indication supported by regulatory approval.
Reading this profile
Jurisdiction: United States; status and indications may differ elsewhere. Molecular class: Synthetic D-amino-acid peptide kappa-opioid receptor agonist.
This profile was written with AI-assisted research and checked against the linked sources. It has not been represented as a clinician’s review. Evidence summaries describe the cited studies and products; they do not establish that a separately purchased preparation is equivalent.
Sources & references
Follow the original material. Product labels define specific formulations and uses; trial registration describes a study and does not by itself establish benefit.
- DailyMed: Korsuva (difelikefalin) prescribing information ↗Regulatory source · Checked 2026-10-27
- KALM-1: phase 3 difelikefalin trial in hemodialysis-associated pruritus ↗Clinical trial source · Checked 2026-10-27