[The efficacy and safety of intravenous bisphosphonates in the treatment of primary hyperparathyroidism complicated by hypercalcemia crisis].

OBJECTIVE

To study the efficacy and adverse events of intravenous bisphosphonates in the treatment of patients of primary hyperparathyroidism (PHPT) complicated by hypercalcemia crisis.

METHODS

From October 2003 to December 2007, 14 patients admitted into our hospital were diagnosed as PHPT complicated by hypercalcemia crisis, which was defined as a serum calcium concentration greater than 3.50 mmol/L. Of them, 6 cases had parathyroid adenoma, 1 had hyperplasia and 7 had parathyroid carcinoma. One of the intravenous bisphosphonates including pamidronate, ibandronate and zoledronic acid was given for 29 times in all the 14 cases. Serum calcium, parathyroid hormone, hematology, and other biochemical markers were monitored. Adverse events were recorded.

RESULTS

After intravenous bisphosphonates, the serum total calcium (Ca) levels decreased from (3.85 +/- 0.50) mmol/L to (2.86 +/- 0.39) mmol/L in (1.4 +/- 0.6) days, and were kept below 3.50 mmol/L for (10.14 +/- 8.54) days. There was no significant difference of the magnitude of decrease in serum Ca levels among the patients using pamidronate, ibandronate or zoledronic acid. The change of serum Ca level was associated with the serum Ca level before treatment. The response to intravenous bisphosphonates evaluated by the decrease of serum total calcium levels was more significant in patients with parathyroid adenoma or hyperplasia than those with parathyroid carcinoma. The most common adverse event was pyrexia, which occurred 15 times (51.7%) and 75% of the pyrexia events occurred after the first infusion. Other manifestations included fatigue, flu-like symptom, myalgia, arthralgia and diarrhea with an incidence of 3.4% each (one event in the 29 times of treatment). There were 2 events (6.7%) with mild increase of serum creatinine concentration.

CONCLUSION

Bisphosphonates can decrease serum total calcium levels in hypercalcemia crisis caused by PHPT effectively with mild adverse events.