Chronic Kidney Disease
Progressive loss of kidney function over months to years. CKD affects peptide drug dosing because many peptides are cleared renally. Difelikefalin is specifically approved for pruritus (severe itching) in CKD patients on haemodialysis. Etelcalcetide treats secondary hyperparathyroidism in CKD dialysis patients.
Technical Context
CKD is classified by GFR category (G1-G5) and albuminuria category (A1-A3). Prevalence: approximately 10-15% of adults globally. Progression: GFR declines at variable rates; reaching G5 (GFR <15 mL/min) requires renal replacement therapy (dialysis or transplantation). Peptide drug relevance: difelikefalin (IV formulation) is approved specifically for CKD-associated pruritus in haemodialysis patients — it is administered after each dialysis session via the venous line; renal dose adjustments are required for many peptide drugs because peptide fragments are renally cleared; GLP-1 RAs are being investigated for kidney protection in diabetic CKD — the semaglutide FLOW trial showed significant reduction in kidney disease progression; and dehydration from GLP-1 RA gastrointestinal side effects can precipitate acute kidney injury in CKD patients, requiring careful hydration counselling.