Successful Use of Difelikefalin in Severe Chronic Kidney Disease-Associated Pruritus in a Patient With Complex Etiological Contributors: A Case Report.

Abstract

Introduction: Chronic kidney disease-associated pruritus (CKD-aP) is a frequently experienced, unpleasant skin condition. Difelikefalin, an agonist of the kappa opioid receptor, is indicated for the treatment of moderate-to-severe CKD-aP in adult patients on hemodialysis. Reports of the effectiveness of difelikefalin in complex patient cases encountered in routine clinical practice are rare. Case Presentation: The presented patient had a complex interplay of morbidities, most notably diabetes mellitus type 2, tertiary hyperparathyroidism, end-stage renal disease (ESRD), and CKD-associated mineral bone disease (CKD-MBD), all of which are associated with the development and severity of CKD-aP. The patient's CKD-aP was resistant to H₁-receptor antagonists and gabapentin and showed no improvement after parathyroidectomy. Treatment with difelikefalin rapidly and sustainably improved symptoms, with a brief recurrence of itching toward the end of each long interdialytic interval. Apart from a short episode of vertigo at the initiation of treatment, no adverse events were observed over the long duration of treatment (currently more than 2.5 years). Conclusion: In a patient with longstanding conditions and multiple comorbidities, difelikefalin showed sustained effectiveness against H₁-receptor antagonist- and gabapentin-resistant CKD-aP. Difelikefalin was well tolerated over the long term.