[Disodium pamidronate (APD) in therapy of hypercalcemia in primary hyperparathyroidism]

The established pre-operative therapy for severe hypercalcemia caused by primary hyperparathyroidism (pHPT), i.e., rehydration with saline in combination with furosemide, calcitonin and hydrocortisone, rarely leads to satisfactory results. We examined the effect of pamidronate (APD, 45-60 mg), a diphosphonate of the 2nd generation in 6 patients (4 female, 2 male) with severe hypercalcemia caused by pHPT. Prior administration of saline, furosemide, calcitonin and oral diphosphonates of the 1st and 2nd generation had failed and the patients still suffered from symptoms of hypercalcemia. APD reduced serum calcium levels in all patients: values reached the normal range (2.1-2.6 mmol/l) in 3 patients, the upper normal range in 2 patients and fell transiently into the subnormal range in 1 patient. In parallel to the decreasing calcium levels a marked increase in PTH was registered in 4 out of 6 patients. One patient with an adenoma showed no change in PTH levels, whereas one patient with hyperplasia of 5 parathyroid glands showed a significant decrease in PTH. These results confirm the potent hypocalcemic effect of pamidronate even in patients whose serum calcium could not be reduced by other conservative therapeutic strategies. Thus, pamidronate is an effective drug in the treatment of the pre-operative phase of hypercalcemia caused by pHPT.