Preventing and treating high levels of parathyroid hormone in certain patients with chronic kidney disease. Zemplar is a vitamin D compound. It works by blocking the formation and release of parathyroid hormone (PTH).
Zemplar is used to treat and prevent secondary hyperparathyroidism (overactive parathyroid glands) in patients with chronic kidney disease. Hyperparathyroidism is a silent condition (causing no symptoms) caused when kidney function declines. Secondary hyperparathyroidism is very common in people in Stages 4 and 5 of chronic kidney disease and can cause the parathyroid glands to become permanently enlarged. Zemplar works by preventing the production of too much parathyroid hormone.