calcitriol + cinacalcet

A combination therapy consisting of calcitriol (an active form of vitamin D) and cinacalcet (a calcimimetic agent). This combination is primarily used to treat secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease, particularly those on maintenance hemodialysis. The drugs work through complementary mechanisms - calcitriol regulates calcium metabolism while cinacalcet increases the sensitivity of calcium-sensing receptors in the parathyroid gland, thereby reducing parathyroid hormone (PTH) secretion without increasing serum calcium and phosphate levels. Clinical studies show this combination is more effective than calcitriol alone in treating moderate to severe SHPT, with significant improvements in iPTH, calcium, and phosphorus levels, as well as beneficial effects on bone metabolism.