[Evaluation of the treatment efficacy of secondary hyperparathyroidism with oral pulse doses of alphacalcidol].

The purpose of the study was to evaluate the effectiveness of the oral pulse therapy with high doses of alphacalcidol (1 alpha(OH)D3) in secondary hyperparathyroidism. 16 hemodialysis patients with 4 to 9-fold iPTH serum elevation were given ones in week oral 1 alpha(OH)D3 in doses from 5.0 to 7.0 micrograms (0.1 microgram/b.m.) according to serum levels of calcium, phosphate, activity of alkaline phosphatase with its bone fraction. Serum iPTH levels were measured every 3rd month of the treatment. The dialysate calcium was reduced to 1.25 mmol/l. CaCO3 was used as a main phosphate binder in doses from 3.0 to 9.0 g/day. After first three months of treatment the serum iPTH levels decreased from 486.0 +/- 200 pg/ml to 218.0 +/- 117 pg/ml (p = 0.0001). Calcium levels increased from 2.39 +/- 0.2 mmol/l to 2.52 +/- 0.29 mmol/l (p > 0.05). Phosphate levels increased from 2.15 +/- 0.67 mmol/l to 2.17 +/- 0.62 mmol/l (p > 0.05). Alkaline phosphatase levels decreased from 35.2 +/- 17.3 IU/l to 31.1 +/- 7.78 IU/l (p > 0.05). Bone isoenzyme of alkaline phosphatase decreased from 19.2 +/- 13.4 IU/l to 15.5 +/- 7.51 IU/l (p > 0.05). Because of early serum hypercalcemia, doses of 1 alpha(OH)D3 had to be reduced in 2 patients. In 8 patients (50%) demonstrating decrease of serum iPTH levels (below 200 pg/ml) after first 3 months of treatment doses of 1 alpha(OH)D3 were reduced in the following months. We conclude that oral 1 alpha (OH)D3 pulse therapy is effective for parathyroid activity suppression in patients with severe hyperparathyroidism. To avoid dangerous hypercalcemia and adynamic bone disease serum iPTH and calcium levels should be strictly monitored.