MINERALIZATION DEFECT BUT NO EFFECT ON HYPERCALCEMIA DURING CLODRONATE TREATMENT IN SECONDARY HYPERPARATHYROIDISM

In four patients with severe secondary hyperparathyroidism, treatment with clodronate caused no decrease in serum calcium. In one of the pat ients treatment for seven months was associated with a severe minerali zation defect which was not caused by aluminium. This lesion was rever sible upon termination of clodronate treatment. In a single patient wi thout hyperparathyroidism, a precipitous decrease in serum calcium was observed due to clodronate. However, long-term treatment with clodron ate did not ameliorate ectopic calcification in this patient. It is co ncluded that in severe secondary hyperparathyroidism, clodronate does not always decrease serum calcium. Our experience suggest that clodron ate like other bisphosphonates may inhibit bone mineralization.