Efficacy and Safety of Long Term Treatment of Unresponsive Hypoparathyroidism Using Multipulse Subcutaneous Infusion of Teriparatide

Abstract

Vitamin D nonresponsive hypoparathyroidism is uncommonly seen in the clinical practice. The use of new treatment modalities, including teriparatide administration, provides an alternative requiring its validation. We report the first case of hypoparathyroidism refractory to vitamin D that was successfully controlled for 5 years by teriparatide treatment. A 53-year-old woman presented severe hypoparathyroidism after thyroidectomy. No therapeutic response was obtained with oral and i. v. calcium and magnesium, or even with 5 μg calcitriol/day. Digestive disorders were ruled out and heterologous parathyroid transplant was ineffective. Subcutaneous (s. c.) recombinant human PTH 1-34 (rhPTH-teriparatide) plus oral calcitriol, calcium, and magnesium, were partially effective, but effectiveness of 20 μg teriparatide lasted less than 4 h and stable calcemia was not possible even with 4-6 injections/day. Multipulse s. c. pump driven infusion of teriparatide achieved complete normalization of serum calcium, phosphate, magnesium, calciuria, and magnesuria with relatively low teriparatide doses (25-35 μg/day) after the first day of treatment. Effectiveness of this treatment modality was maintained for 5 years. The only significant side effect observed during these years was the development of subcutaneous nodules with occasional insufficient control of calcemia. A gain in bone mineral density was observed after the first year of treatment, which had remained stable and within normal values, thereafter until now. No abnormalities in bone scintigraphy were detected in the follow-up. Vitamin D unresponsive hypoparathyroidism maybe safely and effectively controlled at long term by s. c. multipulse pump treatment recombinant human PTH.