Efficacy of intravenous alfacalcidol in the treatment of secondary hyperparathyroidism in patients on hemodialysis.
BACKGROUND
Secondary hyperparathyroidism remains a serious problem in hemodialysis patients. The therapy of renal osteodystrophy is mainly based on lowering phosphate levels and administering vitamin D(3) metabolites and calcimimetic agents.


METHODS
An observational, prospective, multicenter study was made to evaluate the efficacy of alfacalcidol in 185 chronic hemodialysis patients with secondary hyperparathyroidism (i-PTH >150 pg/ml). Patients with a CaxP product >70 were excluded. Intermittent therapy with intravenous alfacalcidol was observed for 6 months.


RESULTS
The mean dose of alfacalcidol per week was 3.63 +/- 1.71 microg. Patients previously treated with vitamin D(3) metabolites needed higher doses of alfacalcidol (4.0 +/- 1.7 vs. 3.2 +/- 1.6; p = 0.01). Only 50.8% of the patients had received vitamin D(3) metabolites prior to the start of the study and at baseline they had higher i-PTH levels (600.3 +/- 360.5 vs. 489.9 +/- 292.6, p = 0.02). i-PTH levels decreased from 546 +/- 332.6 to 332.4 +/- 274.5 pg/ml (p < 0.001). 60.5% of the patients had i-PTH < 300 pg/ml at the last observation. Serum calcium increased (9.4 +/- 0.8 to 9.97 +/- 1.0 mg/l, p < 0.001).


CONCLUSION
Alfacalcidol reduced the levels of i-PTH and produced a slight increase in serum calcium and phosphate levels. In mild or moderate hyperparathyroidism the doses needed were lower than in severe hyperparathyroidism.