Failure of cimetidine to suppress immunoreactive parathyroid hormone and hypercalcaemia in primary hyperparathyroidism.

Cimetidine has been reported as suppressing the excess parathyroid hormone secretion and hypercalcaemia seen in hyperparathyroidism. A case of primary hyperparathyroidism is described, in which the level of circulating parathyroid hormone and hypercalcaemia remain entirely unaffected by cimetidine. The drug is implicated in the management of primary hyperparathyroidism unsuitable for surgery, but present evidence, as reviewed, is insufficient to recommend the use of cimetidine in this way.