Impact of recombinant PTH on management of hypoparathyroidism: a systematic review

The treatment of post-surgical hypoparathyroidism (following thyroid or parathyroid surgery) is challenging. Presently, this condition is treated with calcium and vitamin D supplements rather than replacing the missing parathyroid hormone. Not only is it challenging to maintain normocalcaemia, but concerns of hypercalciuria and ectopic calcification have also been raised using these supplements. There is an ongoing debate whether recombinant parathyroid hormone (rPTH), which as yet is unlicensed for treating hypoPTH, may offer a more physiological solution. The objective of the study was to assess the effectiveness and safety of rPTH in maintaining normocalcaemia and normocalcuria in hypoparathyroidism. This was a systematic review performed using independently developed search strategies including Medline, Embase, CINAHL, Cochrane, Zetoc, conference proceedings and a manual search until 15 July 2014. Data extraction was undertaken by one reviewer (YR). Studies were synthesised through narrative review with tabulation of results. Of 2,141 studies identified, only eleven studies fitted the inclusion criteria. These studies suggest that rPTH is useful in normalising serum calcium levels. Excretion of urinary calcium levels is reduced with PTH 1-34 but remained unchanged in a number of studies using PTH 1-84. Recombinant PTH is well tolerated. The majority of studies included post-surgical hypoparathyroidism with marked heterogeneity. Further prospective, larger, long-term trials are necessary to evaluate the long-term efficacy and adverse profile of rPTH, including head to head comparisons between PTH 1-34 and PTH 1-84.