Long-term effects of histamine H2-receptor antagonists on serum parathyroid hormone in chronic renal failure.

We assessed the effects of ranitidine and cimetidine (histamine H2-receptor antagonists) on the serum concentrations of parathyroid hormone (PTH) in 22 patients with end-stage chronic renal failure. Treatment for 3 months induced a significant decrease in serum concentrations of PTH determined by radioimmunoassay directed at the mid portion of the PTH molecule. In contrast, significant increases were noted using an assay directed at the amino-terminal portion, whereas no change was noted with a carboxy-terminal assay. No significant changes in serum calcium, phosphate and alkaline phosphatase were noted after treatment with either agent, but serum concentrations of osteocalcin increased significantly. We conclude the H2-receptor antagonists do not favourably influence the natural history of hyperparathyroid bone disease in patients with end-stage chronic renal failure.