[Verapamil in primary hyperparathyroidism]

In a female patient with primary hyperparathyroidism and disturbances of cardiovascular function clinical, biochemical and electrocardiographic as well as bone scintigraphic parameters were analyzed before and during therapy with verapamil (Falicard) for 7 month. Verapamil therapy resulted in decrease of the frequency of the supraventricular tachycardia, and, in higher doses (4 X 120 mg), also reduction of blood pressure, however, with dose limiting bradycardia and prolongation of PQ-time. Both the normalization of serum phosphate level, diminution of hypercalcemia of the ionized calcium and the decrease of hypercalciuria and increase of scintigraphic index as an expression of the decrease of high activity of bone metabolism suggest alterations of the calcium homeostasis. Under oral calcium load the constantly increased PTH values markedly could be suppressed indicating an alteration of intracellular parathyroid calcium set point. Discussion is performed with respect to possible protective metabolic and cardiovascular effects of calcium antagonists in this endocrine functional disorder.