**1. Introduction**

In patients with end-stage renal disease (ESRD), parathyroid hyperplasia, high circulation parathyroid hormone (PTH), and hyperphosphatemia characterize secondary hyperparathyroidism (SHPT).

SHPT is a serious manifestation of chronic kidney disease (CKD) with negative effects on patients' life quality and outcome.

In ESRD, medical treatment for secondary hyperparathyroidism has three main strategies: reduction of P uptake by dialysis, dietary restriction, and/or P-binders; calcimimetics; and vitamin D.

Due to toxicity, aluminum-based P-binders have been replaced by those containing Ca salts. At high doses, Ca-based P-binders may elevate the risk of vascular calcification. Ca-free P-binders with dietary P restriction appear to lower fibroblast growth factor-23 and improve cardiovascular and renal outcomes in patients with SHPT [1].

Despite the availability of several P-binders, the ideal P-binder that combines high efficacy, low pill burden, minimal side effects (including gastro-intestine), and low cost is still not available [2], and the effect on survival is unclear [3].

In EDRD patients, vitamin D may improve abnormal mineral homeostasis; however, a steady escalation of vitamin D analog dose is not feasible due to hypercalcemia, hyperphosphatemia, and/or parathyroid gland resistance, despite the concurrent use of calcimimetics [4].

Calcimimetics such as cinacalcet therapy are currently a class of agents that activate the Ca sensing receptor and potentiate the effect of extracellular Ca. Literature supports cinacalcet therapy to improve patients' outcomes, especially with regard to vascular calcifications and presumably the very lethal condition of calciphylaxis [5].

Additional clinical evidence suggests that cinacalcet in combination with low-dose vitamin D is more effective in lower PTH than calcitriol alone. However, cinacalcet is administered orally and has been associated with gastrointestinal intolerance along with hypocalcemia [6].

In addition, poor adherence has been observed among dialysis patients selfadministering cinacalcet [5]. Cost effectiveness is another consideration; the addition of cinacalcet contracts an additional US\$3000–4000 per year on the top of the costs of vitamin D and P-binders [7].

If calcimimetics side effects are intolerable, some researchers have reported that parathyroidectomy may be more cost-effective than cinacalcet in some patients with ESRD and suffering from uncontrolled SHPT [4].
