Cinacalcet in combination with vitamin D therapy has no effect on parathyroid hormone (PTH) levels in dialysis patients with secondary hyperparathyroidism (SHPT) compared with vitamin D alone, but the dual regimen does improve calcium and other mineral parameters, according to investigators.
Hongying Peng, MD, of the Affiliated Baiyun Hospital of Guizhou Medical University in China, and colleagues conducted a meta-analysis of 8 randomized-controlled trials of 1480 patients comparing dual therapy and monotherapy. The combination of cinacalcet (typically 30 mg/day) and vitamin D significantly lowered serum calcium, phosphorus, and calcium × phosphorus product compared with vitamin D monotherapy, according to results in International Urology and Nephrology. Investigators found no significant differences in mean serum PTH, 30% or greater reduction in PTH, or the proportion of patients attaining target PTH of 150 to 300 pg/mL.
With respect to adverse events, dual therapy did not significantly increase all-cause mortality, diarrhea, muscle spasms, or headache, compared with vitamin D monotherapy, but it was associated with a significant 18-fold higher risk of hypocalcemia and a greater than 3-fold higher risk of nausea or vomiting.
Due to the heterogeneity of the studies, small sample sizes, and short durations of included trials, the investigators believe larger and longer-term studies are still needed to assess the effects of cinacalcet plus vitamin D on PTH level, cardiovascular events, and other important clinical outcomes.
Xu J, Yang Y, Ma L, et al. Cinacalcet plus vitamin D versus vitamin D alone for the treatment of secondary hyperparathyroidism in patients undergoing dialysis: a meta‑analysis of randomized controlled trials [published online September 17, 2019]. Intl Urol Nephrol. doi:10.1007/s11255-019-02271-6