Teriparatide for Postsurgical Hypoparathyroidism

This study evaluated the effects of teriparatide (Forteo) on low calcium levels in the setting of thyroid surgery associated with low parathyroid hormone. The hypothesis was that teriparatide ( Forteo) would shorten the length of hospitalization post thyroidectomy in patients with symptomatic hypoparathyroidism.

Transient hypoparathyroidism with hypocalcemia occurs in up to 20 % of patients after surgery for thyroid cancer, multinodular goiter or Graves' disease and is severe in around 3 to 18% of cases. Severe hypocalcemia significantly lengthens their hospital stay. This study will evaluate the effects of teriparatide (synthetic parathyroid hormone, brand name Forteo) on low calcium levels in the setting of thyroid surgery associated with low parathyroid hormone. This was a feasibility open-label, single-arm trial with historical matched controls with a planned enrollment of 15 patients with severe, symptomatic hypocalcemia that would be treated with teriparatide for a maximum duration of 3 weeks and compared the active subjects with 30 gender and age matched controls. Therapy for hypocalcemia continued in accordance with current practice. The decision for discharge, as far as calcium is concerned, was to be reached when calcium level was > 7.5 mg/dL and increased x 2 over 12 hours in an asymptomatic patient with stable therapy and no need for IV calcium in the last 24 hours. Subjects were followed by phone and with blood tests 2 days after discharge and 9, 17 and 25 days after initiation of teriparatide. They were off teriparatide for 24 hours prior to testing on days 9, 17 and 25. If hypocalcemia recurred after 2nd week, teriparatide was continued for a 3rd week and then discontinued. If hypocalcemia recurred again current standard therapy for hypoparathyroidism was continued off teriparatide.

The dose of teriparatide will be 20 mcg twice daily for the first week and 20 mcg daily for the second week. If hypocalcemia recurs after 2nd week, teriparatide will be continued for a 3rd week and then discontinued.

The dose of teriparatide will be 20 mcg twice daily for the first week and 20 mcg daily for the second week. If hypocalcemia recurs after 2nd week, teriparatide will be continued for a 3rd week and then discontinued.

Hospital length of stay from initiation of therapy with calcium and calcitriol to "ready to discharge" from a calcium perspective (calcium level > 7.5 mg/dL and increasing x 2 over 12 hours in an asymptomatic patient with stable therapy and no need for intravenous (IV) calcium in last 24 hours).

Inclusion criteria: Patients post bilateral thyroid bed surgery (cancer, Graves disease, multinodular goiter) Symptomatic hypocalcemia Total calcium < 8 mg/dL persisting after 24 hours of therapy with calcitriol (minimum 0.25 mcg twice a day) and calcium supplementation (minimum 1.5 grams of elemental calcium per day) Parathyroid hormone (PTH) level below low end of normal range Exclusion criteria (all subjects): Renal failure Any prior parathyroid pathology Pre-existing hypercalcemia Metabolic bone diseases other than osteoporosis Pagets disease Exclusion criteria (active treatment subjects only): Ongoing therapy with Forteo for osteoporosis Active non-thyroidal malignancy or suspicion of residual thyroid malignancy History of skeletal malignancies, primary or metastatic Pregnancy Active or recent urolithiasis Digitalis therapy Patients at increased baseline risk for osteosarcoma, i.e., family history of osteosarcoma or prior radiation therapy involving the skeleton Pediatric populations Unexplained elevations of alkaline phosphatase