Reduction by Cimetidine of Serum Parathyroid Hormone Levels in Uremic Patients

Abstract
Dietary restriction of phosphorus1 , 2 and administration of antacids3 have been shown to prevent or reverse uremic hyperparathyroidism, but patients find this therapy unpalatable and difficult to maintain. Recent case reports suggest a decrease of circulating levels of immunoreactive parathyroid hormone (iPTH) with cimetidine in two patients with primary hyperparathyroidism and ulcer disease.4 , 5 We therefore evaluated the effects of cimetidine on circulating levels of iPTH, ionized calcium, magnesium, and phosphorus in patients on maintenance hemodialysis for end-stage renal disease. We found that cimetidine reversibly lowered iPTH levels without affecting serum concentrations of calcium, phosphorus, or magnesium.MethodsSeven patients (five men . . .