Difelikefalin, sold under the brand name Korsuva, is an opioid peptide used for the treatment of moderate to severe itch.

[10] Activation of KORs on peripheral nerve terminals results in the inhibition of ion channels responsible for afferent nerve activity, causing reduced transmission of pain signals, while activation of KORs expressed by immune system cells results in reduced release of proinflammatory, nerve-sensitizing mediators (e.g., prostaglandins).

[17] The applicant for this medicinal product is Vifor Fresenius Medical Care Renal Pharma France.

[13] Due to its peripheral selectivity, difelikefalin lacks the central side effects like sedation, dysphoria, and hallucinations of previous KOR-acting analgesics such as pentazocine and phenazocine.

[11][13] It has also completed a phase III clinical trial for uremic pruritus in hemodialysis patients.