Introduction: Calcimimetics are highly efficient drugs in treatment of secondary hyperparathyroidism (sHPT) in patients on haemodialysis. The effect and the dose of cinacalcet may depend on severity of sHPT, and alfacalcidol supplementation helps in the treatment optimization. The study evaluated cinacalcet and alfacalcidol treatment efficacy in haemodialysis patients with different secondary hyperparathyroidism severity recognized by iPTH.
Material and methods: The study group comprised of 82 participants (male 67 and 34 female) in aged from 36 to 75 years, on haemodialysis. All patients were divided into two groups: the study group--40 participants treated with cinacalcet accompanied by alfacalcidol started after 8 months of the study (0.25 to 0.5 microg/day) and the control group--42 patients. The study group comprises of two subgroups: I--moderate sHPT with iPTH 500 to 800 pg/ml and II--severe sHPT with iPTH > 800 pg/ml. The basic phosphate binder treatment throughout the study period in all groups was calcium carbonate.
Results: In the subgroup I initial mean iPTH 700 +/- 129 pg/ml was reduced to 550 +/- 61 pg/ml (p < 0.05) in the third month with no need of the Mimpara dose change. No further iPTH decrease up to eighth month of the treatment was observed despite the cinacalcet dose increase to 53 mg (p < 0.05). The alfacalcidol supplementation decreased iPTH to 331 +/-55 pg/ml (p < 0.05) and the cynacalcet dose to 42 mg (p < 0.05). In the II subgroup iPTH was reduced from 1035 +/- 149 pg/ml to 885 +/- 101 pg/ml (p < 0.05) in the third month of the treatment and Mimpara dose changed to 90 mg. Up to eighth month iPTH did not change (790 +/- 92 pg/ml; p > 0.05) despite the cinacalcet dose increase to 122 mg (p < 0.05). The alfacalcidol supplementation induced iPTH reduction to 622 +/- 71 pg/ml (p < 0.05) and the cinacalcet dose to 100 mg (p < 0.05).
Conclusions: Cinacalcet convinced its effectiveness in the iPTH serum concentration control in haemodialysis patients independently of secondary hyperparathyroidism severity and alfacalcidol supplementation enhanced its efficacy. Still in case of the late introduction of Mimpara this drug was recognized as potent however the efficient dose was mandatory multiply.