SYMPTOMATIC HYPOCALCEMIA IN A PATIENT WITH LATENT HYPOPARATHYROIDISM AND BREAST-CARCINOMA WITH BONE METASTASIS FOLLOWING ADMINISTRATION OF PAMIDRONATE

Pamidronate is an effective drug used not only in patients with tumor- associated hypercalcemia, but also in normocalcemic patients with meta static bone disease to relieve pains. We describe a 39-year-old normoc alcemic patient with subclinical hypoparathyroidism and bone metastasi s due to breast carcinoma. Following parenteral administration of 60 m g pamidronate, the corrected serum level of calcium decreased from 2.1 2 mmol/l (=8.9 mg/dl) to 1.42 mmol/l (5.7 mg/dl), accompanied with car pal pedal spasm. The present case indicates that the hypocalcemia due to latent hypoparathyroidism was compensated by extensive osteolysis d ue to bone metastasis, and that overt hypocalcemia may develop after i ntravenous administration of pamidronate in such a patient.